Document JNpgoeyk4GmJDoKzOk276kE0a

S T 08 50584 THE JOURNAL OF INDUSTRIAL HYGIENE EDITORS DAVID L. EDSALL M. D.. S. D.. United State* EDGAR L COLLIS, M. D., M. R. C. S., Great Britain VOLUME XIII JANUARY, 1931--DECEMBER, 1931 THE CHEMICAL LIBRARY MIDLAND. MICHIGAN PUBLISHED BY HARVARD SCHOOL OF PUBLIC HEALTH Boiton, Mass. ST 0850586 CONTENTS OF VOLUME Xlll JANUARY, 1931. NUMBER 1 rioi Thb National Institute of Health of the United States Public Health Service. H. S. Cumming, M.D., Surgeon General............... 1 The Kata-Thebmometer as an Anemometer. T. Bedford, Ph.D., and C. G. Warner, B.Sc. From the Industrial Health Researoh Board, London............................................................................................. 4 ^Rational Method for Calculating Records Obtained bt Means ' /. of Owens' Jet Dust Counting Apparatus. Dr. M. Kagan and ' ' Dr. W. Broumstein, Laboratory of Hygiene, State Institute of Labor Protection, Moscow.................................................................................... 10 " Coal Miners' Lung: A Radiographic Study of Certain Groups of Industrially Healthy South Wales Coal Miners. The King Edward VII Welsh National Memorial Association................................ 19 Book Notices................................................................................................. 45 l-/ t FEBRUARY, 1931. NUMBER 2 ^Linseed Dermatitis. M. H. Barnes,M.D.................................................. jBmplotment "Sickness and Death Rates." Harold W. Stevens, M.D... -Studies on Experimental Pneumonokoniosis. VI. Inhalation of Asbestos Dust: Its Effect upon Primary Tuberculous Infec tion. Leroy U. Gardner and Donald E. Cummings. From the Saranac Laboratory for the Study of Tuberculosis, the Edward L. Trudeau Foundation, Saranac Lake, New York..................................... Book Notices................................................................................................. 49 + 56 65 82 MARCH, 1931. NUMBER 3 A Method of Staining the Asbestosis Bodies Found in the Sputum of Asbesto8 Workers. S. Roodhouse Gloyne, M.D., D.P.H., Pathol ogist, City of London Hospital for Diseases of the Heart and Lungs, Victoria Park, London................................................................................ 85 The Toxicity of Certain Benzene Derivattveb and Related Com pounds. Henry Field Smyth, M.D., Dr.P.H., Assistant Professor of Industrial Hygiene, University of Pennsylvania........................... .. 87 "* Studies on Experimental Pneumonokoniosis. VI. Inhalation of Asbestob Dust: Its Effect upon Primary Tuberculous Infec tion (Concluded). Leroy U. Gardner and Donald E. Cummings. From the Saranac Laboratory for the Study of Tuberculosis, the Edward L. Trudeau Foundation, Saranac Lake, New York.................. 97 ST 0850587 Iv THE JOURNAL OF INDUSTRIAL HYGIENE . The So-Called Cyanide Rash. M. W. von Bemewifcz............................. 115 BooxNotice8............................................................................................... 116 APRIL, 1931. NUMBER 4 Dangers in Refining Radioactive Substances. Herman Schlundt, William McGavock, Jr., and Mildred Brown, University of Missouri, Columbia, Mo............................................................................................ 117 The Reduction of Mine Am Temperatures. T. Bedford, Ph.D., and C. G. Warner, B.Sc. From the Industrial Health Research Board, London....................................................................................................... 135 A Colorimetric Method for the Detection and Estimation of Small Amounts of Lead. Edward W. Kraus and J. B. Ficklen, Chemical Laboratory, The Travelers Insurance Company and The Travelers Indemnity Company................................................................ 140 Book Notices................................................................................................... 144 MAY, 1931. NUMBER 5 The Importance of the Points of Contact in Electric Injuries. Orthello R. Langworthy and William B. Kouwenhoven. From the Departments of Neurology and Electrical Engineering, The Johns Hopkins University, Baltimore, Md........................................................ 145 Physical Impairment among One Thousand Negro Factory Workers. Floyd P. Allen, M.D., Associate Secretary, Public Health Federation; Executive Secretary, Heart Council, Cincinnati, Ohio........................... 157 Cardiovascular Impairment among One Thousand Negro Factory Workers. Floyd P. Allen, M.D., Associate Secretary, Public Health Federation; Executive Secretary, Heart Council, Cincinnati, Ohio............................................................................................................ 164 The International Silicosis Conference Held at Johannesburg, August, 1930. Charles Badham, M.B., B.Sc., D.P.H., Medical Officer of Industrial Hygiene, Department of Public Health, New South Wales; an Australian Delegate...................................................... 169 Book Notices................................................................................................... 183 JUNE, 1931. NUMBER 6 The Subjective Side of Fatigue in Industry. Rex B. Hersey, Assist ant Professor of Industry, and Research Associate, Industrial Research Department, University of Pennsylvania................................................ 185 J- The Carcinogenic Potency of Mineral Oils. C. C. Twort and J. M. Twort, Manchester Committee on Cancer, Manchester University... 204 * -fNoTB on the Determination of Small Amounts of Benzene Vapors in Air. Henry F. Smyth, Jr., M.S. From the Laboratory of Hygiene and Public Health, University of Pennsylvania...................................... 227 Book Notices................................................................................................... 231 a P40S . 115 . 118 t> i, . 117 d 1, . 135 F b ie . 140 . 144 8. ie is . 145 8. a; .. 157 ;Y th tij .. 164 G, al ;w .. 169 .. 183 3tch .. 185 M. .. 204 RS sne .. 227 .. 231 CONTENTS ST0850588 SEPTEMBER, 1931. NUMBER 7 rAoa Butchers' Dermatitis. Benjamin Schwartz, Ph.D., Senior Zoologist, Bureau of Animal Industry, United States Department of Agriculture.. 233 ? sA Stott of Dysmenorrhea at the Home Office of the Metropolitan r.nm Insurance Company. Ruth E. Ewing, M.D., Metropolitan Life V . Insurance Company, New York City........................................................ 244 Observations on the Working Capacity of Coal Miners in Relation to Atmospheric Conditions. T. Bedford, Ph.D., and C. G. Warner, B.Sc. From the Industrial Health Research Board, London.............. 252 A New Instrument for Measuring Cooling Power: The Coolometer. : Walter S. Weeks, Professor of Mining,University ofCalifornia........... 261 . u . fikNoncES..................................................................................................... 266 rjlgfjW,. v. ' OCTOBER, 1931. NUMBER 8 ^v|,A Night Industrial Dental Clinic in Montreal. R. Vance Ward, ^ M.D., and Frank G. Pedley, M.D., Montreal,Canada............................ 269 ^viTHE Toxicity of Methyl Chloride for Laboratory Animals. John L. . White and Paul P. Somers, Bureau of Laboratories and Research, De- cjjjfc partment of Health, Chicago...................................................................... 273 ` 'The RAle of Punctate Basophilia in the Control of Industrial Plumbism. Ronald E. Lane, M.B., B.S. (Lond.), M.R.C.P. (Lond.)......................................................................................................... 276 Quantitative Measurements of the Inhalation, Retention, and , V Exhalation of Dusts and Fumes by Man: II. Concentrations below 50 Mo. per Cubic Meter. Carlton E. Brown, Department of Industrial Hygiene, Harvard School ofPublic Health, Boston, Mass. . 285 Book Notices................................................................................................ 292 NOVEMBER, 1931. NUMBER 9 Studies in Dubt Retention: III. Factors Involved in the Reten tion of Inhaled Dusts and Fumes by Man. Carlton E. Brown, De partment of Industrial Hygiene, Harvard School of Public Health, Boston, Mass.............................................................................................. 293 Hypertension in Industry. E. J. Kirk, A.B., M.D., Department of Internal Medicine, University of Nebraska, College of Medicine, Omaha......................................................................................................... 314 Injuries Produced in the Organism by the Discharge from an Imfuwe Generator. Orthello R. Langworthy and William B. Kouwenhoven. From the Departments of Neurology and Electrical Engineering, The Johns Hopkins University, Baltimore, Md................ 326 Book Notices................................................................................................ 331 ST 0850589 vi THE JOURNAL OE INDUSTRIAL HYGIENE DECEMBER, 1931. NUMBER 10 FAQI The Production of Carbon Monoxide from Paint in Sealed Com partments. J. S. Dudding, S. F. Dudley, and R. C. Frederick, Royal Naval Medical School, Greenwioh........................................................... 333 Portable Motor-Driven Impinqer Unit tor Determination of Sulphur Dioxide. Richard Brooke Smith, Consultant on Air Pollu tion, and B. S. T. Friis. From the Laboratory of Richard Brooke Smith, Boston, Mass................................................................................. 338 The Dust Hazard in the Abrasive Industry: Third Study. W. Irving Clark, M.D., Norton Company, Worcester, Mass................................. 343 Heat Cramps m Industry: Their Treatment and Prevention by Means of Sodium Chloride. Donald M: Glover, M.D., F.A.C.S., Visiting Surgeon, St. Luke's Hospital and City Hospital, Cleveland___ 347 Index to Volume XIII................................................................................... 361 ST0850590 furnish j funda-j d death! he facts] toward! alme ons and! iologist ent offiJ itoba >f unem-j [STUDIES ON EXPERIMENTAL PNEUMONOKONIOSIS. VI. INHA LATION OF ASBESTOS DUST: ITS EFFECT UPON PRIMARY TUBERCULOUS INFECTION* Leroy U. Gardner and Donald E. Cummings From the Saranac Laboratory for the Study of Tuberculotit The Edward L. Trudeau Foundation, Saranac Lake, New York I HE experimental investigation of the reaction to inhaled as, bestos dust had long been conItemplated as a part of the study of Bpneumonokoniosis carried on at the Laboratory during the past since so much interest has recently been manifested in the subject of asbestosis, a preliminary report is sub mitted at this time. Asbestos Dust ^twelve years. During that time little -.attention had been paid to the inj;halation of asbestos dust as the cause |.of industrial disease. It was hoped -that this substance might be investiKgated, because it is a relatively soft 1 soluble silicate, the study of whose faction might shed some light upon % several of the vexing problems arising . Injconnection with the inhalation of : hard silicious dusts. It admirably : suited our plans, therefore, to comply with a suggestion of Dr. Frederick L. Hoffman, that we undertake an ex perimental investigation of the reac tion to this substance. At the request of Dr. Hoffman, the Asbestos Corpora^ tion of America has furnished the Laboratory with 600 pounds of exedingly fine asbestos dust from its plant at Thetford, Quebec. The ex periment was started in January, 1928, and animals have now been deposed for two years and five months. The study is not yet completed, but * Hficeived for publication July 18, 1930. The dust employed in this study when dry is a light, fluffy, gray-white, stringy substance, composed of short fibers and irregular particles. Com mercially this grade of asbestos is known as "King's floats." For a proper understanding of its physical characteristics, a brief consideration of its occurrence in nature and its method of preparation is necessary. The Thetford asbestos is known as chrysotile, a member of the serpentine group of minerals. Pure chrysotile is a silky, white, fibrous substance, but the presence of iron in varying states of oxidation usually gives it a greenish or greenish-brown color. It is com posed of tightly packed bundles of smooth, flexible fibers, which are about 0.05 micron in diameter, and which vary from 1/8 inch to 6 inches in length. In nature these fibers occur in veins, which are embedded in hard serpentine rock. The thickness of the vein determines the length of the fibers, which run across it. 65 Vol. u No.} ST085059: 66 THE JOURNAL OF INDUSTRIAL HYGIENE The King's floats grade of asbestos contains only short fibers which occur in very narrow veins. The hard ser pentine matrix, rich in small veins, is crushed, dried, recrushed, screened and pulverized, and finally passed over shaking screens from which the fibers are withdrawn by suction. The ma terial is then graded by screening, and the fraction which passes the finest screen is allowed to settle in a large room. Such material (King's floats) contains not only short fibers, but in The dust has a specific gravity of 2.26. It loses only about 1 per cent, of its weight when heated at 110C., yet in a moist atmosphere sufficient water is absorbed to increase notice ably its tendency to clumping or matting. In chemical composition, pure chrysotile is chiefly composed of crys talline hydrated silicate of magnesium (3MgO-2SiO-2HjO). It is, however, seldom free from impurities which partially replace the magnesium to form more complex silicates. Ferrous iron is the most oommon contaminant, and it may sometimes constitute as much as 10 per cent, of the mineral as it occurs in nature. A portion of this iron may be oxidized to the ferric state. The following analysis has been made from samples of the dust used in the study: addition many small particles of ser pentine rock. Microscopic examination reveals the fact that particulate matter is far in excess of fibrous material. The par ticles vary in size from 10 microns to 0.5 micron in diameter. The fibrous traction is less uniform. In length the fibers vary from 1 mm. to 1 micron or less. Many isolated, long, smooth, thin, flexible strands are seen, while others consist of short thick bundles with broken ends. The fibers are highly refractiie when viewed by polar ized light. (See Fig 1.) % Total SiOs.................................. 38.32' Fe0, AI.O,................................ 8.84 CaO............................................ 0.67 MgO............................................ 35.56 Alkalies and loss........................ 2.87 Combined water......................... 12.74 'Free SiOi (by rational analysis) = 2.8%. The material reported as aluminium oxide and ferric oxide was largely the latter. Preparations of the dust stained with potassium ferricyanide and dilute hydrochloric acid indicate that there is ferrouB iron in the ma jority of the fibers; a few exhibit irregular staining with ferrocyanide. Anderson and Clark (1) have shown that treatment of Thetford chrysotile with hydrochloric acid completely destroys the typical crystalline pattern j. I. H. Feb., 1WI S T 0 8 50592 REACTION TO INHALED ASBESTOS DUST 67 `v < been ; used H of the material produced in Bragg's X-ray diffraction technic. Careful and repeated search has fnilftd to disclose any yellow structures resembling asbestosis bodies in the dust previous to its residence in the animal. The appearance and method of development of these structures will be discussed later. Experimental Procedures The general plan of the experiment is the same as that previously em ployed in studies on granite (2), marble (3), carborundum (4), and ' quartz (5). In the present instance, animals are kept in cages along the wallB of a room 6 by 8 feet, and 8 feet high, provided with two 3 by 5 foot windows. A cloud of dust is maintained in the atmosphere of this room by apparatus located in an . alcove, 6 feet from the nearest animal. ' This apparatus consists in a horizon tal drum 2 1/2 feet long and 1 1/2 feet in diameter, placed 8 inches above the floor. Its top is open, and in it rotates a metal paddle, whose shaft projects through the end of the drum and then through the partition into an adjacent room in which is located an electric motor. By properly selec ted pulleys and countershafting, the speed is so regulated that the desired dust concentration can be maintained. Ventilation is secured by opening one of the windows an inch or more from the top. The animals are kept, gen erally in pairs, in 12 by 12 by 12 inch wire cages set on racks at the sides and back of the room. While it will be Bhown that the dust concentration progressively decreases from the floor to the ceiling, this factor is compen sated by frequently changing the position of the cages on the racks. As measured by the operation of the motor, the daily period of exposure is eight hours, but since the animals remain in this room during the night, the actual exposure is much longer, considerable time being required for all the dust in the atmosphere to settle. In warm weather the period is some what shortened by opening the win dows when the motor is stopped in the evening. From the commencement of the experiment on Jan. 20, 1928, until the present date, the dust exposures have been continued for eight hours, on six days a week, with the exception of a period of three weeks in the month of January, 1930, when the motor was being repaired. Dust Concentration The amount of dust in the atmos phere of this room has been checked with a Greenburg-Smith impinger apparatus.1 Samples taken on Feb. 14, 1928, one month after the experi ment was started, showed the concen trations given in Table 1. The rate of suction on the sampling apparatus was 1 cubic foot per minute; the sampling times were fifteen min utes and thirty minutes. Owing to the fibrous nature of the dust, the particles were not filtered before the counts were made, but the very large particles (those greater than 100 microns) were simply neglected in counting. Particles over 1.5 microns in diameter, magnified ninety-five times, were counted in the usual manner in a Sedgewick-Rafter cell, 1 Appreciation is expressed to Mr. Morris Dworski for making these duBt determina tions. J. I. H. b,, 1831 Vol. U '.L-No, ] ST0850593 68 THE JOURNAL OF INDUSTRIAL HYGIENE after being allowed to settle for thirty minutes. The smaller ones varying from 1.5 microns to 0.5 micron in diameter were counted in a hemocytometer chamber at a magnification of 410. The usual blank controls on the distilled water used to collect the dust samples were made, and the number of accidental particles was subtracted before the results were tabulated. ThiB concentration was maintained with little variation until January, 1930, when the speed of the paddle was accelerated, and the amount of sus days before the dust inhalation was begun; forty of them were placed in the dusting room and twenty-three were kept in a normal atmosphere as controls. Two years after the experi ment was started, twelve dusted and twelve normal guinea-pigs were in fected with tubercle bacilli. This group was then set aside without fur ther exposure to the dust. All the rats and rabbits and fifty-four of the guinea-pigs were used in studying the uncomplicated effects of inhaled asbes tos dust. Each of the various groups will be described separately. TABLE 1.--DUST COUNTS HEIGHT OF COUNT NO. INTAKE FROM FLOOR MILLION PARTICLES PER CUBIC FOOT OF AIR A IOO-IOm (X 95) B 10-1.5m <X 95) C 10-0.6n (X 410) D 1.5d or less (C -B) Total (A + C) ft. i 2 1.130 8.033 56.668 48.633 57.796 2 2 1.258 6.625 51.600 44.975 52.858 Average.. 1.194 7.329 54.133 46.804 55.645 3 4 Average.. 4 4 0.450 0.400 0.425 4.960 4 440 4.700 35.000 43.333 39.166 30.040 38.893 34.466 35.450 43.733 39.591 pended dust was increased approxi mately ten times. The majority of the animals to be discussed in this report, however, were subjected only to the smaller dust concentration. In this experiment 128 guinea-pigs, eighteen white rats, and seven rabbits have thus far been used. A portion of the guinea-pigs were infected with tubercle bacilli in an attempt to determine the influence of this dust upon a tuberculous process. One group of sixty-three guinea-pigs were infected with tubercle bacilli four Pathologic Lesions Non-Tuberculous Guinea-Pigs Up to the present date, twenty-nine months after the commencement of the dust inhalation, fourteen animals, or 26 per cent, of the group, have died of epizootic pneumonia, and fifteen more succumbed to other conditions, such as enteritis and peritonitis. As this experiment was designed to demonstrate the maximum effects which could be produced by the in haled dust, relatively few of the ani- j. I. H. Feb., U31 iere as 7.796 2 858 5.645 9.591 igs ty-nine lent of inimals, ,ve died fifteen ditions, tis. As ied to effects the inthe ani- J. I. H. Feb., l3l ST085059U REACTION TO INHALED ASBESTOS DOST 69 mals have been killed. A number have, however, been sacrificed at 30, 60, 90, 354, 610, 782, and 847 days. Commencing with the eighth month of exposure, the effects of the dust have also been followed radiographi cally in the living animals. The pulmonary localization of in haled asbestos differs from that of any other dust thus far studied. Granite, quartz, carborundum, and soft coal particles penetrate the terminal air spaces of the lung, and large quantities ultimately localize in the subpleural alveoli. Asbestos dust, presumably because it is so largely composed of elongated fibers, is carried by the in spired air only to the distal respiratory bronchioles, and there the major portion of the material comes to rest. Mononuclear phagocytes from the adjacent connective tissues enter the lumen of the air passages and engulf the particles. The phagocytes with their contained fragments of dust are frequently pushed aside into the alveoli which pouch out of the sides of the bronchioles, where many of them remain indefinitely. More dust entering the lung is held up by the partial obstruction created, and fur ther reaction is largely proximal to the point of original localization. A few particles pass beyond into the proximal portions of the alveolar ducts, but in the majority of cases the deposition of asbestos dust occurs within respiratory bronchioles of the second and third orders and in the alveoli given off directly from those structures. (Fig. 2.) In guinea-pigs killed thirty days after starting the dust inhalation, occasional small mononuclear phago cytes containing a number of brown or black particles and a few short spicules of doubly rcfractile material are visible in the alveoli budding off from the respiratory bronchioles. A few' multinucleated dust cells are Fig. 2.--Crow section of lungs of guineapig exposed to asbestoB dust inhalation 840 days. Normal size. Fig. 3.--Roentgenogram of guinea-pig exposed 880 days to asbestos inhalation. encountered. The lymphoid tissues of the bronchial tree exhibit a moderate degree of hyperplasia. The lymphatic trunks coursing through the bronchial walls are wide open, but no dust cells or other material can be found in Vol. 13 No. 2 ST0850595 70 THE JOURNAL OF INDUSTRIAL HYGIENE their lumina. The tracheobronchial lymph nodes exhibit no more dust containing cells than those in any normal animal kept in a laboratory atmosphere. At sixty days, the number and size of the dust cells in the terminal respira tory bronchioles is considerably in creased. The lumina of some of the lateral alveoli are completely blocked by masses of mononuclear phagocytes and larger giant cells. Some of the latter have six or more nuclei. Fre quently in Zenker-fixed tissues, these phagocytes have a diffuse yellowbrown color which is presumably due to the presence of dissolved iron in their cytoplasm. In tissues fixfed in formalin and stained with acidified potassium ferrocyanide, such cells exhibit a diffuse blue coloration. 5 In addition, there are certain particles in their cytoplasm stained very - deep blue which are probably the source from which the iron is ^dissolved. Doubly refractile intracellillar spidulea are numerous; they are most read ily demonstrated in polarized light, ^fter sixty days' exposure totlust, the first evidence of that peculiar structure Which has been called a "curious body" is detected. We prefer to adopt Stewart and Haddow's (6) designation of "asbestosis body," and shall use the latter term exclusively. After two months the number of asbestosis bodies is small and they are atypical in appearance. The most common form is a club-shaped swelling at the end of a smooth pale greenish fiber. Some present small fusiform swellings along the course of a short fiber. They are seen almost without exception inside of large giant cells. After ninety days' exposure, the number of these structures has very markedly increased, and they have assumed > their typical form. The smaller ones are still contained in giant cells, but many long forms appear to be free in the stroma of the lung. The amount of cellular reaction has not kept pace with the number and size of the foreign bodies. It still con sists of collections of mononuclear and giant phagocytes within the lumen of a localized group of air spaces, together with a very slight infiltration of the adjacent septa. Hyperplasia has occurred in the lymphoid tissues associated with the bronchi proximal to the foci of maximum dust reaction, but no phagocytes have carried dust particles into the lymph nodules. The lymphatic trunks are widely distended, but they contain no cells or dust particles. The tracheobron chial lymph nodes also show wellmarked hyperplasia, but the number of dust containing cells is still Bmall. During the next four months, no animals were killed, but nine died of various accidental causes. In them it is found that increasing quantities of dust are accumulating in the vicinity of the respiratory bronchioles, and that the amount of cellular reaction is some what increased. Asbestosis bodies are so extremely abundant that as many as eight have been encountered in an oil immersion field. They are prac tically absent in other portions of the lung. The other changes in the lymphoid tissues and lymphatic ves sels remain much the same. There is as yet no evidence that appreciable amounts of dust are being transported to the tracheobronchial lymph nodes. In three guinea-pigs killed on the 357th day, the amount of reaction has J. I. H. Feb.. 1031 S T 0 8 50596 REACTION TO INHALED ASBESTOS DUST 71 developed to such a degree as to be visible on gross section of the fixed lar appearance with ill-defined borders. They are arranged radially on the sur face and suggest a relationship to the A. vA V V; r' r. - ` '/. T A' ; : '. 'v-vV Fio. 4.--Longitudinal section of bronchus . and its peripheral branches. Exposure 357 ''days. Approximately X45. Note that duBt y,reaction is localized to region of respiratory bronchioles. No reaction in lymphoid tiscues. V, Fia. 6.--Peribronchiolar dust reaction in normal guinea-pig exposed 840 days. Connective tissue stain. Approximately X90. pracof the i the c veslere is ciable Dorted nodes, in the on has J. I. H. Feb.. >M1 - * : < Longitudinal section of bronchus ana its peripheral branches. Exposure 436 aays. Approximately X45. Note that dust bronchiole 0ca*'zed t0 region of respiratory tissue. Uniformly distributed over , en^e surface of both lungs are fine : .r 'yellowish-white ovoid flecks of granu Fig. 7.--Early tuberculous reaction in focus of asbestosis; endogenous extension 357 days after infection. Approximately X90. finer bronchioles. All are of approxi mately the same size and none exceed 1 mm. in diameter. Microscopically those foci are similar in every way to Jt-Vol. 13 No. 1 ST 0850597 72 THE JOURNAL OF INDUSTRIAL HYGIENE the type of reaction already described. of the air spaces adjacent to the The walls of the bronchioles, proximal deposits of accumulated dust phago to alveolar ducts, are thick, but this cytes. At first only a few cells are is due solely to an excessive local involved, but after still another 100 accumulation of phagocytes. There dayB, a true fibrosis, accompanied by is no evidence that fibroblasts are the formation of very considerable proliferating. The dust cells have amounts of collagen, has developed. not migrated to any extent from the The walls become progressively thicker, original foci of localization; none are and encroach upon the lumen of the found in the pulmonary lymphoid air spaces. The epithelium of the tissues, but some have been trans latter contracts and becomes cuboidal, ported to the tracheobronchial lymph so that the area of reaction resembles nodes. (Figs. 4-7.) In the medullary a gland with a heavy connective tissue sinuses of the latter location there are stroma. The Iumina of these gland now definite clusters of brown-stained like atelectatic air spaces are more or iron containing phagocytes. In their less completely filled with compact cytoplasm many irregular black or masses of dust cells and brown- brown particles and refractile elon stained giant phagocytes whose cyto gated spicules are recognizable. Occa plasm is gorged with dust particles, sionally a giant cell is seen partially fibers, and asbestosis bodies. In the surrounding a very long fiber which thickened septums there are many of may project beyond the limits of the the latter, which are generally extra cell. One such fiber measured 25 cellular. (Figs. 6,9, and 10.) microns in length. No asbestosis The amount of dust carried into the bodies are seen. As yet the only tracheobronchial lymph nodes now evidence of reaction in these nodes becomes, more abundant. It consists consists in an active proliferation of largely of amorphous or granular the follicle cells. black or brown particles with many While asbestosis bodies cannot yet doubly refractile spicules which fail be found in the lymphoid tissues, they to stain specifically for iron. Occa do occur outside the lung. Two of sionally a few giant cells, sometimes in the 357-day animals had developed a small clusters, contain typical asbesto chronic fibrous pleurisy, and occa sis bodies. The stroma of the nodes sionally in the connective tissue there about the masses of dust cells now are small clusters of phagocytes con exhibits a limited amount of fibro taining dust and asbestosis bodies. In blastic proliferation. an isolated field, five of them have The latest stages of the reaction of been counted. asbestos dust thus far produced are On the 449th day, two asbestosis manifested in the lungs of five guinea- bodies are found within a giant cell in pigs, of which three were killed on the the tracheobronchial lymph nodes. 782nd day, and one on the 840th day. All animals killed or dying on and All five exhibited a large number of after the 505th day are characterized subpleural gray-white nodules at least by the proliferation of fibroblasts. 1 mm. in diameter, uniformly dis This reaction is confined to the walls tributed over the surface of the lung. J. I. H. F.b,, 1931 ST0850598 REACTION TO INHALED ASBESTOS DUST 73 ,he On section of the organs, sharply The first radiographic examination 10- demarcated ovoid areas are disclosed to demonstrate definite changes in the ire in every part of the lung. One lung was obtained after a dust expo00 animal shows a fibrous pleurisy over by ble ;d. er, .he he al, les ;ue id- or ict n- co- ea, he of ra- Fia. 8.--Peribronchiolar focus of asbestoais; guinea-pig exposed 782 days. Approx imately X70. Flo. 10.--Magnified field of Figure 8. Connective tissue stain. Note strands of collagen between gland-like alveoli. Ap proximately X140. he ow sts lar ny ail ta- in to tes ow ro of ire Fia. 9.--Magnified field of Figure 8. Fig. 11.--Asbestosis in rabbit exposed ;ahe Note gland-like air spaces. Approximately i wU. 149days. Approximately X140. Note giant cells, one of which has invaded nodule of lymphoid tissue. iy- portions of the lung without evidence of of an underlying pneumonia. The sure of two years. At this time the iSt tracheobronchial lymph nodes are presence of very fine mottling was lis- deeply pigmented in their central detected in the lower portions of the ig- portions. lung fields. After another five months H. Vol. 13 1831 No. 2 ST 0850599 74 THE JOURNAL OF INDUSTRIAL HYGIENE had elapsed the changes had become much more marked. As illustrated in Figure 3, they" consist of strands of coarse mottling which radiate outward and downward from the hilum. The outlines of,the mediastinum and the pericardium ar^ obscured by similar shadows. Whether the apexes are also involved cannot be definitely determined. , s Pathologic changes ibythe lungs of experimental animals are-much more readily demonstrated radiographically if the lungs are removed from the thorax and inflated before exposure to the X-ray. Roentgenograms have been made in this manner of animals with well-developed asbestosis and the shadows produced are characterized by a pronounced thickening of the linear markings which extend outward from along the main bronchi to the margins of the lung. Microscopically, the lungs present lesions similar to those already de scribed, but they are more extensive and fibrosis has become more marked. In stains for connective tissue, abun dant collagen formation is now apparent in the walls of the respiratory bronchi oles and their alveoli. Dust cells and asbestosis bodies are very abundant. The extension of the process from the terminal bronchioles proximally into respiratory bronchioles of greater di ameter is obvious. In addition to these characteristic changes, the lung of one animal exhibits more or less circumscribed foci of fibrosis in the alveolar septums peripheral to the usual reaction zone. The lumina of the included air spaces are normal in size, and apparently fully distended. Their walls are lined with easily visible cuboidal or flattened epithelium which occasionally dips into the thickened septums to form gland like structures. In marked contrast to the previously mentioned areas of fibrosis in the respiratory bronchioles, these more peripheral foci include practically no dust cells or asbestosis bodies. One lobe of this lung is covered by organized fibrous pleurisy which also fails to exhibit dust deposits. Examination of the trachea and stem bronchi, both by direct and by polar ized light has failed to demonstrate appreciable amounts of dust or local reaction. The only evidence of irrita tion is the presence of an occasional polynuclear leukocyte on the ciliated surface and the. distention of the goblet cells with mucus. More periph erally the connective tissue coats of the bronchi of the second and third orders exhibit considerable infiltration with lymphoid cells, and some engorge ment of the blood vessels. The other viscera, the spleen, liver, kidneys, pancreas, and abdominal lymph nodes have been uniformly free of dust or evidence of reaction attributable to it. In the guinea-pig, the development of the early (two years and five months) response to inhaled asbestos dust may be summarized as follows: The particles and elongated fibers of asbestos dust do not, during this period, penetrate so deeply into the air passages of the lung as do the other dusts previously studied. The major portion is held up and phagocytosed in the lumina of respiratory bronchioles and the alveoli given off from their walls. Increasingly large masses of phagocytes accumulate in the lumina of these air spaces, and many of the cells migrate into the framework of J. I. H. - Fb., 1931 ere of this he air other najor jed in hides their es of imina jf the irk of j. i. H. eb.. 1931 ST0850600 REACTION TO INHALED ASBESTOS DUST 75 the adjacent lung tissue. In this location there develops a low grade chronic inflammatory reaction charac terized by infiltration with monocytes and a few lymphoid cells. Approxi mately 500 days after the commence ment of dust inhalation, the connective tissue cells in the walls of the bronchi ole and its alveoli begin to proliferate. Thereafter, the reaction is charac terized by increasing amounts of fibrous tissue which develops in the ; immediate vicinity of the dust cells. The thickening stroma encroaches . upon the lumen of the air spaces whose 1 -. epithelium, being compressed, appears ' cuboidal, as is the case in pulmonary atelectasis. The picture produced somewhat resembles glandular tissue. In addition to this lesion, which is characteristic of all the animals exam ined, one of three of the last guinea- . pigs killed showed a further change V; consisting in focal areas of fibrosis in the alveolar septums peripheral in the pulmonary unit to the point of dust localization. Changes- in other structures of the lung are not striking. There is wellmarked hyperplasia of the lymphoid tissues in the periphery of the lung, but dust containing phagocytes do not migrate toward and enter these masses, as is the case with quartz inhalation. Dilatation of the large lymphatic vessels in the connective tissues of the bronchi and blood vessels has been a constant finding in all the animals of the series. Even thirty days of dust inhalation would appear sufficient to Produce this effect. Its cause has not j**611 (^8C0Vered; thrombi within the lumen of the lymph vessels are lacking, - and a central obstructive lesion in the I?, traoheobronchial lymph node is a late development. Only after 700 days do fibroblasts begin to proliferate in the medulla of the nodes. Asbestosis bodies have not been found in any animal killed before sixty days of dust exposure. When first discovered, they are small, some what atypical in form, and generally contained within the cytoplasm of phagocytes. Within the next sixty days they rapidly increase in number, size, and complexity of structure. The larger ones appear to be liberated from the cells, and ultimately to be free in the air passages or intracellular spaces. In most cases, these struc tures, presumably because of their size, are not transported from the point where they first develop in the lung. Occasionally they have been found in the tracheobronchial lymph nodes and in areas of chronic fibrous pleurisy. In these instances they are usually intracellular. Rabbits Five rabbits exposed to asbestos dust for 40, 53, 149, 253, and 330 days, respectively, have thus far been killed and studied. Within the period of time included, the reaction to the inhaled dust has been characterized by increasingly large focal collections of mononuclear and giant phagocytes. These, as in the guinea-pig, tend to accumulate in and along the respira tory bronchioles, although in the last two animals killed, some collections of dust cells have been seen in the more peripheral air spaces. In marked contrast to their behavior in the guinea-pigs, the phagocytes exhibit a tendency to migrate into masses of lymphoid tissue. This occurs early, and has been observed in all but the fKe.i ST085060 I 76 THE JOURNAL OF INDUSTRIAL HYGIENE first animal killed. It is probably due 1929, six new, apparently healthy rats to anatomic differences in the two were placed in the dust room. During species. In the rabbit, abundant a period of 118 days three have been deposits of tonsil-like lymphoid tissue sacrificed and one has died. All of are situated directly beneath the epi them have had pulmonary abscesses. thelium throughout the course of the In only one animal, which was killed on bronchial tree; in the guinea-pig the the seventieth day, could asbestosis lymphoid nodules are not so readily bodies be detected, and in this case accessible. The phagocytes are filled prolonged search of smears of the lung with great quantities of doubly refrac- tissue stained for iron has revealed only tile dust spicules, but no typical two of these structures. One was very asbestosis bodies have yet been discovered. small, but typical in appearance. The When stained for iron, none of the other consisted of a bundle of fibers fibers in the first four animals reacted. frayed at the end, and upon one of the In smears of lung tissue from the last fibrils were a few irregular swellings. animal killed on the 330th day, a few In another rat killed after 118 days, elongated fibers exhibited irregular no asbestosis. bodies have been found. deposits of both ferric and ferrous iron, and there were occasional globular The Asbestosis Body swellings along their course. But Since the development of the peculiar these fibers did not present the ubusI structure termed an asbestosis body golden-yellow color of an asbestosis in the lungs of animals compelled to body, and the alterations in structure inhale asbestos dust may have an were in no way characteristic. important bearing upon the general No suggestion of fibrosis or even problem of pneumonokoniosis, it de reaction in the framework of the lung serves detailed consideration. adjacent to the collection of dust cells The forms encountered in the lungs has been discovered, but it is still too of guinea-pigs in every way resemble early to expect much change. In the those pictured in the human cases. guinea-pig, the first indication of While individual specimens exhibit fibrosis was found on the 500th day. marked variations, there are certain Albino Rats features which are characteristic of all the forms observed. The fully Repeated attempts to study the developed body consists of a brilliant reaction to inhaled asbestos in the golden-yellow, beaded or haustral rod, white rat have been defeated by the which may be either straight or curved. development of epizootic pneumonia, Its color resembles that of the hemo often complicated by abscess forma siderin deposits found in areas in which tion. The first series was composed of hemorrhage has occurred. In length twelve animals, all of which buc- they vary from 1 to 250 microns, and cumbed to this infection. One sur in width from 0.5 micron to 10 microns. vived for 450 days, but in all of them The shorter ones are usually straight, the reaction to chronic pneumonia so but the larger forms are curved, or obscured the picture that no deduc even coiled. They do not stain with tions were possible. In December, any of the dyes ordinarily used for J. I. H. Feb.. M31 its -"g en of es. on >si8 osc mg nly ery The >ers the igs. .ys, nd. liar ody i to an eral de- ,.ngs lble ses. libit tain : of ully iant rod, ved. mohich igth and ons. ght, or with for . I. H. 11 ST 0850602 REACTION TO INHALED ASBESTOS DUST 77 tissues, but Wright's blood stain is usual histologic stains have no apparabsorbed to some extent, giving them a ent effect upon them. Iron in the greenish cast. Fixing fluids and the ferric state may be demonstrated by .. ^IQ- 12.--Asbestosis bodies in guinea-pigs' lungs. Nos. 1 to 10 from smears of lung tissues; Nos. 11 and 12 in sections. Approximately X560. *'? 1 shows a smoothly coated fiber; in No. 2, no fiber is visible; No. 7 shows coating material cracked along fiber. Other illustrations show various forms of this structure. Vol. 13 No. 2 ST 0850603 78 THE JOURNAL OF INDUSTRIAL HYGIENE treatment with potassium ferrocyanide in dilute hydrochloric acid (McDonald and Stewart). Examined under polar ized light, they are not doubly retrac tile. The shorter forms are usually found within the cytoplasm of a foreign body giant cell; longer ones the process of preparing sections and smears, cannot be determined. (Fig. 12.) The lung of the rabbit apparently offers a much less favorable environ ment for the production of the asbestosis body than that of the human being Fig. 13.--Atypical aabestoais bodies from lung of rabbit exposed 330 days. Nos. 8 and 9 are artificially produced aabestoais bodies. X840. may be coiled within such cells, but more usually they lie free in the lumen of an alveolus or in the intercellular spaces of the pulmonary framework. Whether they actually exist in the free state during life or whether, owing to their elasticity, they are set free in or the guinea-pig. Nothing faintly resembling one of these structures has been found until the dust exposure has been continued for a period of eleven months. At that time, in hematoxylin and eosin preparations occasional fibers are seen which have a muddy, greenish j. I. H. Feb., 1931 ctioas nined. rently viron:bestobeing Nos. faintly -es has ire has eleven toxylin 1 fibers -eenish j. I. H. Feb.. 1> ST 0850S04 REACTION TO INHALED ASBESTOS DUST 79 hue, but they do not exhibit the regular beading, or the characteristic golden-yellow color seen in the guineapig. Preparations stained for either ferrous or ferric iron demonstrate a few very long fibers containing irregu lar swellings of a deep blue color. Whether typical asbestosis bodies will ever develop in this animal remains to be demonstrated. (Fig. 13, Nos. 3 and 4.) In the lung of the white rat they would also appear to be very uncom mon, although the widespread inci dence of chronic pulmonary infection among the animals thus far exposed, in a measure invalidates the results. Thus far, only two asbestosis bodies have been discovered in one animal of this species. If the environment were favorable, it would seem probable that more of these bodies would have been detected, even in the presence of com plicating pneumonia. I Our observations have led us to believe that the asbestosis body devel ops as the result of chemical changes taking place within or about inhaled asbestos fibers. The dust previous to contact with the pulmonary tissues shows no such structures. A period of time which varies with different species of animals must elapse after the fibers have entered the lung, before the asbestosis body makes its appearance. The first forms encountered are differ ent from those seen later. They con sist of iron containing, sheath-like or nodular swellings along the sides or at the ends of a fiber. From such points further extensions occur until In some cases the whole filament acquires a uniform coating which is brittle (Fig. 12, No. 1). Movement or otherstress causes the coating substance to crack, separating it into segments (Fig. 12, No. 7). Chemical action continues and the segments tend to elongate in a direc tion at right angles to that of the original fiber. Extension also takes place at the ends of the fiber, so that it increases in length. Small fragments may also serve as nuclei for chemical activity; about them spherical or ovoid masses develop. The resultant forms exhibit many variations. Per haps the most common ones consist of an axial fiber traversed at intervals by a variable number of thickened cross bars. Often one end and sometimes both ends are swollen and spindle shaped. In other instances, the cen tral fiber cannot be discovered (pos sibly it has been dissolved?); the body then consists of a row of globules. Sometimes these are of uniform diam eter; frequently they decrease pro gressively from one end to the other. In guinea-pigs exposed for more than two years, many bizarre branching globoid forms are seen, which resemble clusters of tuberous bulbs. An observation which merits com ment is the scarcity of asbestosis bodies in the tracheobronchial lymph nodes. Presumably because of their size, the majority of the inhaled asbestos fibers are not transported to any distance by phagocytes. Never theless, after exposure to the dust has been continued for somewhat over a year, appreciable numbers of doubly refractile non-iron-staining fibers can be found in the lymph nodes of the mediastinum. They are embedded in the cytoplasm of phagocytes which have migrated from the lung. After two years, large masses of such dust cells have accumulated, and yet asbes- VcL U Mb.* ST0350605 80 THE JOURNAL OF INDUSTRIAL HYGIENE tosis bodies are not found in any number in the tracheobronchial lymph nodes. Those which do occur are located in clumps of giant cells. It is believed that the formation of the few asbestosis bodies found took place in the lung, and that they were then transported to the lymph nodes in emboli of phagocytes. Why do asbestosis bodies occur so rarely in the material which has been transported to the lymph nodes? Were the fibers during their period of residence in the lung deprived, by solution, of iron or some other sub stance necessary to their production; or are the transported fibers essentially different from those remaining in the lung; or, again, is the environment furnished in the lung especially favor able for the production of asbestosis bodies? To answer the last possibility, injec tions of asbestos dust have been made into other portions of the body. In the peritoneal cavity of the guinea-pig attempts to produce asbestosis bodies have met with but slight success. In one series each guinea-pig was injected with 2 c.c. of a heavy suspension of the King's floats dust, which was so pre pared by sedimentation (7) that only particles varying from 2 to 4 microns were present. This material, it will be recalled, contains not only asbestos fiber, but a considerable amount of iron and other material. Another series received a like amount of pure asbestos fiber cut and ground into the finest possible state. This fiber was obtained from a vein of Thetford ore. As a control, a third series was injected with a suspension of granite from Lorain County, Ohio. This rock contains free silica and ferrous car bonate, among other constituents. Samples of the peritoneal fluid were withdrawn with capillary pipettes twenty-eight and sixty-four days after the injections. In each series the fluid exhibited large numbers of dust con taining monocytes, and in both the asbestos groups large giant cells were numerous. No sign of an asbestosis body could be discovered. Dissolved iron was detected in the cells from the granite series, but none could be found in those from either of the asbestos groups. On the seventieth day and again on the 110th day, one animal from each group was killed. The amount of reaction was surprisingly insignificant. Careful search revealed minute foci of pigmentation in the omentum of each animal. At seventy days no sugges tion of an asbestosis body was dis covered, but at 110 days a few very small but typical bodies were found in a smear stained for iron of an omental nodule from one animal injected with the King's floats dust. The asbestos fiber and the iron containing granite animals did not show them. These findings were confirmed subsequently by histologic examination of the tissue. While the remaining animals of this experiment are still under observation, it hardly seems probable that asbes tosis bodies will develop in any num ber. Aside from its failure to favor the formation of these structures, it is surprising that the peritoneal cavity exhibits so little reaction to the injec tion of very considerable quantities of this foreign material. When more insoluble dusts, such as coal, quartz, and carborundum, are injected, very appreciable*deposits are found in the j. i. h. Feb., 1931 ents. were >ettes after fluid coni the were stosis olved m the found restos i. I. K. Feb., 1931J ST 0850606 rV REACTION TO INHALED ASBESTOS DUST 81 omentum and beneath the parietal /peritoneum. t. In the subcutaneous tissues, at tempts to form asbestosis bodies have somewhat more successful. In uncompleted experiment designed to determine whether oertain dusts V might cause a dissemination of infec. tion with tubercle bacilli of attenuated V virulence, daily repeated injections of asbestos dust suspensions were made linto the subcutaneous tissue of the i of guinea-pigs previously injected i tubercle bacilli in the same area, ivall, thirty injections totaling 3 of very fine dust (King's floats) i made. Most of the material has yet been examined, but in one lltnimal dying in 102 days, and in three more killed 264 days after the duBt ^Injections were completed, the subcuous tissues exhibited large masses ( foreign body giant cells containing typical asbestosis bodies. tfWith a view to determining whether tie Iron of the asbestosis body is from the dust or from the , animal body, the following experiment ; has been performed. A mixture was iprepared which contained equal parts y. of .very finely divided pure asbestos ' .* fiber , and fine whole asbestos dust (King's floats), the latter composed of particles between 2 and 4 microns in diameter. Both of these elements were included because the pure fiber from asbestos veins contains so little iron. The mixture was divided into two parts, and from one of them the iron was completely removed by digestion with hydrochloric acid and ^ksequent washing. Both fractions .Were Bterilized by heating at 100C. for t one hour, and suspended in physio logic salt solution. The iron free portion formed a smooth turbid opales cent suspension, while the untreated portion produced a gray-green flocculent one. Two c.c. of each of these suspensions were injeoted into the subcutaneous tissues of the groins of each of six guinea-pigs; the untreated suspension on the right side, and the iron free material on the left. When examined thirty days later, all the animals had palpable nodules at the site of injection of tie untreated material, and none on the opposite side. At this time one of the guineapigs was killed. On the right side there was a nodule 10 mm. in diam eter filled with greenish-gray necrotic material, while on the left side there was only a faint suggestion of pigmen tation in a very slightly enlarged superficial inguinal lymph node. Smears made from the material on each side failed to demonstrate goldenyellow bodies. When stained for iron with potassium ferrocyanide, numer ous uniformly blue fibers were seen in the abscess produced by the untreated material, but only a few short, un stained fibers could be discovered in the smears from the opposite side. There was no suggestion of an asbesto sis body. As in the case of the peri toneal cavity, the impression is gained that a part of the dust may have been dissolved in the body fiuids. The effects produced at sixty days were identical. The absence of asbestosis bodies on the right side is attributable to the lack of sufficient time for their development; the disappearance of the injected material on the opposite side is most surprising. (To be concluded) tv S T 08 5060") THE JOURNAL OF INDUSTRIAL HYGIENE Volume XIII MARCH, 1931 Number 3 A METHOD OF STAINING THE ASBESTOSIS BODIES FOUND IN THE SPUTUM OF ASBESTOS WORKERS* S. Roodhousb Gloyne, M.D., D.P.H. r-.V Pathologist, City of London Hospital for Diseases of the Heart and Lunge, Victoria Park, London JWTIHERE is a consensus of opinion that the asbeetosis bodies found in the sputum and lungs of jisbestoe workers do not stain with the '^tbrdinaiy aniline dyes. This failure T stain has been one of the difficulties nj working out their relation to the `logy of the disease and in deterJihining their composition. By em"<'pk)ying the following technic the ^bodies can be made to take on a defi>`**^nite color which enables them to be ifjbetter studied. ' V' Hematoxylin After digestion of the sputum with equal quantities of concentrated anti.ft, formin (as described by Stewart and '^Haddow (1)) and centrifugation, the (j^U'fcntiformin is pipetted off and replaced ,'$y & 5 per cent, solution of Ehrlich's ife^&^h^xylin. Bluing of the hema- hour and then recentrifuged and the deposit mounted as a wet preparation. By this means the asbestosis bodies become a dark brown to black color, according to the length of time they have been exposed to the hematoxylin. Prussian Blue Reaction The reaction of the asbestosis body to Prussian blue was first described by Cooke and Hill (2) and McDonald (3). The foregoing technic is used but the following mixture is substituted for hematoxylin: 2 per cent, potassium ferrocyanide--1 part; 1 per cent, hydrochloric acid--3 parts. With this technic the asbestosis bodies are colored a brilliant blue. A potassium ferricyanide mixture may also be used but the results are variable, some asbestosis bodies being stained, others not. 4iS,,,txylin immediately takes place owing 'V.to the remains of the alkaline antiormin. The mixture is well shaken 1 allowed to stand for a half to one Received for publication Nov. 22,1930. Ammonium Sulphide The same technic is used but am monium sulphide is substituted for hematoxylin or potassium ferrocyanide. The asbestosis bodies are then colored 85 ST035060S 86 THE JOURNAL OF INDUSTRIAL HYGIENE black. This color can be removed with hydrochloric acid. Dibcpsbion When examined microscopically the hematoxylin specimens give the im pression of having hematoxylin de posited on them rather than having actually taken up the stain, but after washing overnight the asbestosis bodies still retain sufficient stain to be colored a dark brown. With the ferrocyanide or ammonium sulphide technic the bodies are homogenously stained. The advantages of this technic are: (1) The minute details of the ashestosis body can be better seen than in the unstained preparation; e.g., the central core of asbestos fiber generally stands out clearly and can sometimes be seen running across a gap between two segments of the asbestosis body Tather like the string between beads on a necklace. The fiber takes on the stain only very lightly--sometimes, indeed, not at all--but the contrast with the stained body is sufficient to demon strate quite clearly its existence. The outlines of the segments are also very clearly seen, and the small subsidiary bosses on the sides of the asbestosis body, and the cracks in the segments are better distinguished by thisjnethod than in the unstained preparation. (2) These reactions support the view that iron enters into the composition of the bodies. The Prussian blue reaction is a well-known test for. iron; and am monium sulphide is universally em ployed as a group reagent for iron. Hematoxylin also has an affinity for iron, but the reaction in this case is inferior to that given by the other methods. The amount of iron found in raw asbestos varies considerably. Accord ing to Merewether (4) the two main varieties of asbestos used in industry are: (1) a larger portion known as chrysotile, a hydrated magnesium silicate with a low percentage of iron oxides (0.7 to 4.4 per cent.); and (2) a smaller portion known as crocidolite, amosite, and tremolite which have a high percentage of iron oxides (3.2 to 44 per cent.). The latter group is the one used in the factory which produces ' the cases seen at this Hospital. Cooke and Hill (5) have also BUggested that blood may enter into the f composition of the asbestosis body, [ Oxyhemoglobin contains 0.335 per fl[ cent, of iron (6). *< *1 ( 1 BIBLIOGRAPHY 1. Stewart, M. J., and Haddow, A. C.: Demonstration of the Peculiar Bodies of Pulmonary Asbestosis (`'Asbestosis Bodies") in Material Obtained by Lung Puncture and in the Sputum. Jour. Path, and Bacteriol., 1929, SB, 172. 2. Cooke, W. E., and Hill, C. F.: Pneumokoniosis Due to Asbestos Dust. Jour. Roy. Micr. Soc., 1927, 47, 232. 3. McDonald, S.: Histology of Pulmonary Asbestosis. Brit. Med. Jour., 1927, *, 1026. 4. Meriwether, E. R. A.: The Occurrence of Pulmonary Fibrosis and Other Pul monary Affections in Asbestos Workers. Tats Jour., 1930, it, 198, 239. 6. Cooks, W. E., and Hill, C. F.: Further ; Observations on Pulmonary Asbestosis,' with Special Reference to Asbestos Dust and the Curious Bodies Found in the Lungs. Jour. Roy. Micr. Soc., 1930, SO, 15. 6. Starling, E. H.: Principles of Human. Physiology. Fourth edition. Lon- j don, J. & A. Churchill, 1926. J. X. H.; Much, 1H1] ST0850609 in rav Accord-} o mail adust iown gnesiufl of irop nd (2) i cidoliti have 3 (3.2 up is i aroduc 1. dso into )ccurreng Other! ,8 Works 19. Aabest i Asbesf b FoundJ tier, of Hu THE toxicity of certain benzene derivatives and RELATED COMPOUNDS* Henry Field Smyth, M.D., Dr.P.H. Attitta.nl Projettor of Industrial Hygiene, University of Pennsylvania Introduction title of this paper may suggeet a very wide range of compounds, about the toxicity of of which we have considerable ation but about that of others Slow little or nothing. I was ty appealed to by an insurance to outline a program for safe ; of a compound that I did not was used in industry and about mcity of which nothing has been so far as I know, never, though the derivatives of Itj are legion, yet they group BjVes into certain main classes, i members of which we have lion. In most cases members s act on the system in a similar i and differences in action are Snoes of degree rather than of ' There are exceptions to this 1 rule, however, some of which ^pointed out later. General Conditions e, CA, is the simplest com(fOf all, and the benzene ring is on which all the others are The so-called homologues of benzene are toluene, CsHs-CHj, and xylene, CeH4-(CH)j, in which one or two methyl radicals replace one or two hydrogens (1). The most important benzene deriva tives industrially and toxicologies lly are the nitro, amino, diamino, and chlor compounds of benzene and tolu ene. Danger to health from these compounds depends not only on their chemical structure but also largely on their physical Btate and the method of handling them. Those compounds responsible for the greatest amount of industrial sickness are not necessarily the most toxic. Homologues of Benzene Considering first the homologues of benzene, toluene and xylene, we find somewhat conflicting reports. Selma Meyer (2) states that regardless of which poison iB acting, whether ben zene, toluene, xylene, naphthalene, aromatic nitro compounds, etc., the lymphocytes are increased in the blood stream and the neutrophils are forced back or repressed. American findings do not agree with this. Neither Greenburg (3) nor we (4) have found toluene or xylene presenting 4 before the Section on Industrial JW the American Public Health , -Fort Worth, Texas, Oct. 28, any characteristic blood picture in experimental animals. Greenburg found that with continuous exposures ` for publication Dec. 15, 1930. for up to seven days, high concentra- 87 ST08506IQ THE JOURNAL OF INDUSTRIAL HYGIENE tions of toluene killed all exposed animals in forty-eight to seventy-two hows with narcosis. Animals sur viving lower oonoentrations showed evidences of narcosis, irritation or depression, with irritability. Our own tests with four-hour exposures over longer periods showed evidences of lung inflammation and of toxic degen eration in internal organs. We both found toluene to be lees toxic than benzene, and the National Safety Council recommended it as a substi tute for benzene where possible (3). In addition to being less toxic, it is less volatile and is less likely to exist in a plant as vapor of toxic concentra tion. Xylene we have found also to be quite toxic, but again it is even less volatile than toluene and therefore less hazardous. Neither of these two substances seems to be readily absorbed through the Hkin in toxic amounts and I know of no case of poisoning from skin absorption due to them. Nitro and Amino Group Compounds Nitro and amino groups, aromatics, in general produoe much the same clinical pictures, differing in some details and with a few striking excep tions. The latter in general are simple blood poisons, while the former in addition exert a direct action on the central nervous system. Floret (5) sayB that all aromatic and aliphatic compounds are fat solvents and there fore particularly apt to affect the central nervous system. In light cases of poisoning from nitro or amino compounds there is flushing of the face, with a sense of fulness and throbbing pain in the head, burning sensation in the throat, and a feeling of tightness in the chest. More marked cases of poisoning develop violent throbbing headache, dizziness, roaring in the ears, and visual disturbances. With still more \ severe poisoning the face beoomes j livid, the lips and tongue blue, the] knees weak, and the gait staggering.] The blue color of the faoe may persist j for several days. In extreme cases] cyanosis increases, muscular tremors] develop, there is extreme weakness,] cold skin, nausea and vomiting, ab-j domlnal cramps, quick, Shallow respi-l ration, lowered blood pressure, and latej unconsciousness. Coma develops, respirations become progressive!^ slower and shallower, involunta urination and defecation may occ and convulsions usually come og just before death. Not infrequent attacks are delayed, coma ooming i even hours after cessation of ex The blood picture is characteristic with reduction in the red cell count i the hemoglobin, poikilocytosis, socytosis, and some fragmentation ; red cells with polychromatoph The blood becomes chocolate color owing to the development of methe oglobin, the spectroscope shov absorption bands between those pure methemoglobin and oxyhemo globin. Evidences of blood regene tion are seen after a few days in noij fatal oases, with the appearance stippled cells and nucleated red ce There is an early polymorpho followed later by a relative lymphfl cytosis. In slow poisoning from cog tinued low exposures there may be i increase in the red cell count, urine becomes brown, port wine ored, or smoky red, and shows bile i blood pigments, methemoglobin hemoglobin. At times albuminu ST08506 Il BENZENE DERIVATIVES AND RELATED COMPOUNDS 89 occuib and the urine may reduce tinued exposure is said to produce Folding's solution. For most of this bladder tumors which may become group the skin is the most important malignant. entry port. The average lethal dose is 25 gm.; Amino Compounds 0.4 to 0.6 mg. per liter of air may be borne without much harm for one- While the amino compounds as a half to one hour but 0.1 to 0.25 mg. r]aa produce a deeper cyanosis than per liter for several hours produces do the nitro compounds, yet with slight symptoms (6). Tests made by them, poisoning is less serious and Issard (7), in 1920, in the aniline recovery usually results in a few days house of a plant while reducers were if exposure is not continued. There being discharged, gave the following are exceptions to this, however. They amounts in milligrams per liter of air: are all very readily absorbed through 0.5, 1.01, 1.18, 2.43, and 3.4--all but -the kin as well as through the lungs. the first one well above the toxic con Aniline poisoning is first manifested centrations. Men were exposed to as an intense cyanosis, the victims of these concentrations for periods of poisoning being referred to as "blue from twenty to forty minutes. One :boys." In an aniline plant visited workman at the plant developed /during the war, cases of poisoning cyanosis from wearing an old pair of occurred daily and blue boys were a gloves found lying in a pool of aniline common sight. Following cyanosis water on a drumhead. Changes in /there develop headache, dizziness, design of apparatus and method /dysphagia, nausea, vomiting, weak relieved this condition and reduced the ness, restlessness, palpitation, and number of poisonings in this depart felfrregular slow respirations with rapid ment almost to the vanishing point; r*feeble heart action. Pupils are con- later, however, the plant started to Jiiacted but respond to light. Tem- develop the production of synthetic 'perature is subnormal. There is an indigo, and new cases began to appear aniline odor on the breath and to the1 in men discharging the phenylglycine sweat. The urine is dark in color driers, as the finely powdered phenyl owing to the presence of hemoglobin. glycine carried more or less absorbed In severe cases there may be a loss of aniline. Here the poisoning was due sphincter controls and also pulmonary to dust inhalation. Two tests taken edema. More cases and more severe by iBzard, in the indigo house while the poisonings occur in hot weather. vacuum driers were being emptied, Workers may develop a degree of showed 0.7 and 1.7 mg. of aniline per tolerance but the cyanosis may persist. liter of air. Continued exposure may result in Toluidines produce the same symp headaches, irritability, poor appetite, toms as does aniline, with less cyanosis neurasthenia, visual disturbances and but more strangury and hemoglobin itching of the eyes which may lead to uria. They produce subnormal tem injury and ulceration of the cornea perature and anemia. Exposure oc from rubbing. There is anemia, with curs from splashes from centrifuges decreased hemoglobin. Long-con and whizzers. :??oLU Wo. i ST08506 I 2 90 THE JOURNAL OF INDUSTRIAL HYGIENE Beta-naphthylamine produces cyan tion available in the literature. Many osis and also frequent urination as a of these preparations were for ubo in result of irritation due to overacid the rubber industry as accelerators or urine. Diamines retarders. Most of these tests have been assembled for comparative pur poses and a.e here presented in the The diamines may be decidedly hope that they may be of interest and toxic. Phenyienediamines are used of help to others called upon to use as dye intermediates in dyeing hair and these materials or to make similar furs. They have been responsible for tests. a number of cases of poisoning from In many cases all that was desired huir dyes and from cheap dyed furs. by those requesting information was Symptoms produced are dermatitis, the determination of the minimum sleeplessness, dizziness, and weakness; lethal dose, as an indication of the and epileptiform convulsions, coma, possibility of accidental acute poi and death may result. The reaction soning. With others the effects of may develop very suddenly and be of repeated sublethal doses were studied. anaphylactic type. Some writers have All experimental work was done with insisted that it was a true anaphylaxiB, small animals, it being the custom in and Curschmann has suggested cal our laboratory to use at least two cium therapy with the inhalation of types of animal, often three, for suoh Bprayed solutions of calcium salts. work. The animals of choice, for Most writers, however, now attribute convenience in handling, are white the poisoning to quinone intermediates rats, guinea-pigs, and rabbits. Dos resulting from incomplete oxidation, ages are always given as grams per and state that care to secure complete ' kilo of body weight of the animal at the oxidation and careful, thorough wash time of administration. It is custom ing of dyed furs will prevent the ary to interpret the results of such trouble from developing. Phenylene- tests in terms of grams per kilo of body diamine should never be used in hair I weight of man, but we always give dyes. Buch interpretation with considerable Tolylenediamine is a blood poison, reserve, and feel that at best it indi producing destruction of red cells, cates an approximation to the range of methemoglobin, and toxic jaundice toxicity for man, rather than an actual with liver degeneration, but is less measurement of it. When used for toxic than the phenyl salt. comparison of the toxicity of different Animal Expeetments compounds, however, we feel that such teste are a very fair indication of rela At various times in the past few tive harmfulness. years our laboratory has been called When death occurs within a com upon to determine the toxicity of a paratively few hours from a single dose number of benzene derivatives and of a chemical, we rarely find micro allied substances, more or less com scopic evidence of toxic organ degener plex, about whose effects on the ation, and in these cases we report only system there was little or no informa doBe, time of death, symptoms, and 1.1. H. Maroh, 1U1 e. Many for use in lerators or tests have ative purted in the iterest and pon to use ,ke similar 7ss desired nation was minimum cion of the acute poi. effects of ere studied, is done with' e custom in t least two ee, for such choice, for. are white bbits. Dos3 grams per i inimaiat the] It is custom- j ulta of such r kilo of body j always give] considerable/ best it indi-;| d the range of | ha.n an actual hen used fori cy of different i feel that Buch' cation of rela-J rithin a com- i n a single dose j ,y find micro-.j jrgan degener-i we report only3 ymptoms, and-j J.1H.I Urnrot. ST08506 I 3 BENZENE DERIVATIVES AND RELATED COMPOUNDS 91 gross changes noted at autopsy. When sample of this substance was found to arimil survive more than twenty- be 0.3 gm. per kilo when dissolved in a four hourB, in addition to gross changes weak acid solution and fed as a hydro we always look for histologic changes chloride. With this dose, death oc in internal organs, especially the liver, curred in from three to twelve hours, kidney and spleen, and other organs as preceded by twitchings, convulsions, indicated. When animals survive a collapse, and gasping inspirations. week or more, we usually include urine Diphenylguanidine, CuHuN* or and often blood findings in the reports. (CHNH)i C: NH, with two substi With most of the tests here reported tuted phenyl radicals, also fed as a on for minimum lethal dose determin hydrochloride, killed in from one to ations, no microscopic findings are three hours in a dose of 0.25 gm. per included. The tests to be reported kilo, with the same train of symptoms. were made as parts of six different Triphenylguanidine, CuHnNi or (Cr investigations on materials supplied by HNH)*-C:NCHi, with three phenyl three different industrial firms. Firm radicals, fed as a paste in 0.1 per cent, names and trade names of chemicals or hydrochloric acid, as it would not go compounds are purposely omitted, but completely into solution, killed in empirical and line structural formulas from three to four hours in a dose of are given when known. In some 0.35 gm. per kilo; death was preceded instances, however, there are differ by violent trembling, convulsions, ences of opinion as to the structural gasping, violent chewing motions, and formula of the compounds reported characteristic rolling over, always in upon. When materials to be tested the Bame direction. ' were water soluble, they were fed by The addition of the phenyl radioals pipette in watery solution. When not to the guanidine molecule definitely water soluble, if soluble in dilute acid increased toxicity. The apparent les they were fed as hydrochlorides with sening of toxicity of the tri over the di as little as possible excess acid. product was no doubt due to its Liquids not mixable with water were lessened solubility; even though it fed as a starch paste. Solids insoluble required a larger dose to kill, the prein water or dilute acid were fed as a lethal symptoms were more violent. paste in olive oil or water. In all j Diorthotolylguanidine, CuHjtN* or cases, animals being dosed were held in (C^4CH,NH)t-C:NH, killed in fortythe hand of the operator and it was five minutes in a dose of 0.12 gm. per made sure by personal observation that kilo; this also was fed as a hydro all the material was actually Bwal- chloride in solution. Prostration lowed. Except as noted, all materials developed rapidly, with twitchings, were of the technical grade of purity. irregular shallow breathing, gasping, and cyanosis. Larger doses killed in Guanidine and Guanidine Derivatives twelve minutes. Here the tolyl radi Guanidine, CHN, or (NHj) C '.NH, cal produced a marked increase in is not in itBelf a benzene derivative toxicity. That the tolyl radical does but it enters into compounds that are. not always insure toxicity is seen in the The minimum fatal doBe for a pure case of diorthotolylthiourea, CHN|B VoLU Mo. a ST08506 I 4 92 THE JOURNAL OF INDUSTRIAL HYGIENE or (CtHCHiNB) CS, in which it is combined with & harmless sulphur compound. Here no symptoms were observed with a dose of 4 gin. per kilo, though the same tendency, in a slight degree, was seen to the development of lung hemorrhage as was observed in almost all of these series. Dosages were not increased beyond 4 gm. per kilo because the corresponding dose for man would be tremendous and it was extremely difficult to feed larger doses to animals. With the materials of the guanidine series there was a very sharp line between the fatal dose killing in at most a few houre and the dose from which there was apparent complete recovery. No animal that survived overnight died. The behavior of the animals dying from these materials strongly suggested cyanide poisoning, as did the behavior of one factory employee whose death was possibly the result of an accidental overdose of one of the guanidine derivatives. A series of animals were fed sublethal doses daily of diorthotolylguanidine for up to twelve days. In these animals traces of a substance reducing Fehling's solution appeared in the urine after each feeding, but did not persist overnight. They all devel oped mild albuminuria but no casts, and postmortem examination showed early but not marked liver and kidney changes. There was evidently no rapid cumulative effect. Aniline and Aniline Derivatives and Compounds A number of aniline derivatives were tested and compared with aniline. Aniline itself, CtHjN or CJLNHj, reported in the literature as fatal for man in doses of 0.35 to 1.43 gm. per kilo (as a pure preparation), killed guinea-pigs in doses of 1.75 gm. per kilo when fed as pure aniline Thiooarbanilide, CnHNjS or (CtHtNH)t'CS, a thiourea deriva tive, proved nonfatal in doses of 4 gm. per kilo, fed as a paste in olive oil, though the animals seemed weak and depressed and petechiae were seen in the lungs. Lack of solubility les sened toxicity, as did also the entrance of sulphur. Methylenedianilide, CuHuN, or (C*HiNH)i-CHj, was also nonfatal in doses of 4 gm. per kilo, and no symp toms were observed. This material also was fed as a paste in olive oil, and insolubility probably was the reason for nontoxicity. Paranitroeodimethylanilide, CHrN|0 or N0 C*ELN(CHi)t, a nitroso compound fed as a paste in water, proved to be twice as toxic as aniline, even though not easily dissolved. It was fatal in doses of 0.65 gm. per kilo in from twelve to forty-eight hours, death being preceded by prostration and convulsions, and red staining of the urine. A series of condensation products containing aniline gave interesting results. Formaniline (CjH7N)x or (CfHtN:CHs)z, a combination of two definitely toxic substances but itself soluble with difficulty was not fatal in doses of 4 gm. per kilo< A trade compound, a condensation product of aniline, acetaldehyde and formaldehyde, and another made from aniline, acetaldehyde and carbon disul phide, also very slightly soluble and fed as olive oil pastes, were not fatal in doses of 4 gm. per kilo. Paratoluidine, C*HN orCHG*EU- }. I. H. Much, 1031 ;m. per killed m. per S or deriva>{ 4 gm. ire oil, ak and seen in ty lesntrance Nt or fatal in > sympaateriai oil, and reason CiHtnitroso water, aniline, /ed. It per kilo , hours, stration ining of iroducts ereeting 1 of two S ut itself 9 .fatalin 9 ensation 9 yde and 9 ide from 9 ondisul- 9 9lble and t fatal in 9 9L-C*Hr 9}. I. H. Uucb. 1931 M ST08506I 5 BENZENE DERIVATIVES AND RELATED COMPOUNDS 93 (pure preparation) fed as a twenty to forty hours in a dose of 2.5 paste in water, killed in a dose of 1.1 gm. per kilo, with mild convulsions, gm. per kilo. This was surprising as and the 4-chloro compound killed in Hamilton (1) quotes Gibbs and Hare forty hours in a dose of 3.5 gm. per as giving 0.1 gm. per kilo as fatal for kilo, with no convulsions. Both were animals. fed in pastes as they were apparently Anhydroformaldejiyde-paratolui- insoluble. Here the position of the dine, (CiHaN)* or (CHj CjELN: C9i),, chlorine atom seemed to govern the fed as a paste in 0.1 per cent, hydro- degree of toxicity. ohlorio acid, was less toxio, the fatal Two polychlorodiphenyls, the defi dose being 2 gm. per kilo, killing in nite compositions of which were unde twelve hours; death was preceded by cided, proved nontoxic in doBes of 4 trembling and kicking, but no general gm. per kilo. They were also fed in convulsions occurred. This is the pastes, and were composed of even toluidine analogue of formaniline larger molecules than the monochloro reported previously, and the substitu compounds. tion of toluidine for aniline markedly A 4-nitrodiphenyl, CuH*NOi or increases toxicity. CiH* CJLNOt, in spite of its nitration A condensation product of aniline, was not fatal in doses of 4 gm. per kilo, paratoluidine, butyraldehyde and car owing probably to its insolubility. bon bisulphide was more toxic than anhydroformaldehyde-paratolui dine, Nitrobenzene but not so toxic as p&ratoluidine. It Nitrobenzene, CJL-NO,, decidedly killed in doses of 1.7 gm. per kilo in toxic as a vapor and by skin absorp from two to six hours; death was pre tion, the latter due to its solubility in ceded by prostration and collapse but fat, was less toxic (using a pure prep there were no convulsions. This was aration) than we had anticipated, an oily fluid with presumably a smaller when fed in a starch paste, the fatal molecule than anbydroformaldehyde- dose being 1 gm. per kilo for animals. paratoluidine, and size of molecule seems to bear some inverse ratio to Phenylnaphihylamines toxicity. Both alpha and beta naphthylamine, Diphenyl and Diphenyl Derivatives CioHjN or CioHj-NH*, are decidedly toxic but their phenylated compounds, Technical grade diphenyl, CuHu or CiiHuN or CioH7*NH*CHi, proved CtHt-CtHi, prepared by passing ben very little toxic. The alpha com zene vapor through a red-hot iron pound fed as a paste required 4 gm. per tube, little if at all soluble in water but kilo to kill in three dayB, while the readily soluble in alcohol and ether (8), same dose of the beta compound was was not toxic in doses of 4 gm. per not fatal. Here the alpha position kilo. proved the more toxic. Two chlorodiphenyl preparations, CuH,Cl or CHj CJLC1, were tested Tolylenediamines and both proved Blightly toxic; the We have stated above that tolylene- 2-chloro compound killed in from diamine is a blood poison, producing Vol. 13 No. 1 ST08506 I 6 94 THE JOURNAL OF INDUSTRIAL HYGIENE destruction of red cells, methemoglobin, toxic jaundice, and liver degenera tion. It has, however, been sug gested as a substitute for the phenylenediamines as a hair dye, on the ground of its much lower toxicity. Tests were made with both the para and the meta compounds, CtHioNj or CH4 CHj (NHj)j, the former as an ingredient of a hair dye and the latter as a rubber chemical. Metatolylenediamine was fed as a hydrochloride in water. The fatal dose was 3 gm. per kilo; however, 0.7 gm. per kilo daily for nineteen days was fatal to a guinea-pig, and 0.6 gm. per kilo daily for five days killed a rabbit. In animals surviving several days there was evident definite fatty degeneration and also renal degenera tion. The body fluids were stained with the material and chemical tests showed that some of it was excreted unchanged in the urine. When com bined with unvulcanized rubber it was not extracted from the rubber when that was applied to the skin and held there as a poultice for several hours, though it was very Blowly extracted by a buffered watery solution ranging between a hydrogen ion concentration of 3 and of 7. The toxicity tests for this product seem to agree fairly well with those previously reported by Stadelmann (9) though he did not report in grams per kilo. Paratolylenediamine was tested as an ingredient of a hair dye. For testing, this material was used in solutions of three different strengths as rec ommended for dyeing, containing amounts of the active ingredients ranging from 2 to 39.6 per cent., depending on the depth of color desired. The minimum fatal dose by mouth was found to be about 3.6 gm. of the pure substanoe per kilo--not very toxic. We found , the material toxic to this extent b/'&Ovth and by subcutaneous injection, but could see no evidence of absorption through the unbroken skin. When used as a dye it is oxidized with hydrogen peroxide to bring out the full depth of color. General Patholoot of Entire Series The one outstanding pathologic lesion seen in animals of the series poisoned with the various benzene derivatives was a tendency to extrava sation of blood in the lungB, whether the animal died from the drug or was killed for study. This varied from scattered minute petechiae to larger ecchymoses or even massive lobular or lobar hemorrhage, the severity of the lesion usually paralleling the severity of the poisoning. In order to avoid agonal congestions seen in gassed animals, the animals were killed by rapid severing of the spinal cord. By this method we practically never found such hemorrhagic lung condi tions in normal animals. In snimula surviving several days these lesions were found to be in the process of absorption and they did not eeem to lead to pneumonic conditions, though we should surmise that repeated lesions of this type would lower the resistance of the lung to infection. Similar lung lesions were found post mortem in a fatally poisoned worker who may have been a victim, of the acute effects of one of the guanidine derivatives. J. LH. lUreh, IM1 il dose by it 3.6 gm. kilo--not material tb and by could see i through used as a hydrogen 11 depth of Entire pathologic the series s benzene o extravas, whether rug or was tried from to larger ve lobular severity of leling the In order is seen in were killed pinal cord. ;ally never ong condi- Tn ii.nimn.lfl ese lesions process of ot seem to ns, though repeated lower the infection, ound postied worker tim. of the : guanidine j. i. H. ini ST08506 I 7 benzene derivatives and related compounds 95 In animals which survived several days and then died or were killed for study, there was usually seen some evidence of early toxic liver and kid TABLE 1.--SUMMARY OF TOXICITIES REPORTED Oramt per kilo of body wight for email animals (guinea-pigs and rabbits) ney degeneration. .No animals of Guanidine and Guanidine Derivatives this series survived long enough or had Guanidine................................................ 0.30 sufficient repeated doses to develop Diphenylguanidine............................... 0.26 marked blood changes. With most of these preparations the Triphenylguanidine.............................. 0.36 Diorthotolylguanidine......................... 0.12 Diorthotolylthiourea............................ 4.+ toxicity was rather low. There is very little danger of accidental poisoning in Aniline and Aniline Derivatives and Compounds industry with any material having a Nitrobenzene by mouth....................... 1,00 pninimnm lethal dose of over 0.25 gm. Aniline................................................... 1.75 per kilo, or 17.5 gm. for a man weigh Thiocarbanilide.......................................4,4. lU:: ing 70 kilos. With limits under that Methylenedianilide............................... 4.4. point but over 0.1 gm. per kilo, there Paranitroaodimethylaniline................. 0.66 is little danger in handling the prepara Paratoluidine......................................... l,io tions if their possible toxicity is real ized and reasonable precautions are taken as to dust and fume removal and Condensation Products Formaniline........................................... 4.4. Anhydroformaldehyde-paratoluidine.. 2.0 Formaldehyde personal cleanliness. It must be borne Aniline 4.4- in mind, however, that personal idio Acetaldehyde syncrasy may make exceptions to this rule, and also that fat soluble or lipoid soluble materials, if water insoluble, may poison by skin absorption in doses not toxic by mouth. Aniline | Acetaldehyde >............................... 4.4Carbon bisulphide] Aniline Paratoluidine [............................ 1.7 Butyraldehyde It must be emphasized that the Carbon bisulphide toxicities here reported refer only to Diphenyl and Diphenyl Derivatives administration of solids or liquids by mouth. As previously stated, fat or lipoid soluble substances may be decidedly more toxic by skin absorp tion than by oral ingestion; also it muBt be borne in mind that the same may be true of vapor inhalation. Therefore these results do not neces sarily represent the hazards of indus trial exposure to vapors or to skin absorption. Diphenyl............................................ 4.42-chlorodiphenyl............................... ..2.6 4-chlorodiphenyl............................... .3.5 Polychlorodiphenyl, A..................... ...4.4Polychlorodiphenyl, B..................... .4.4- Phenylnaphthylamines Phenyl-alpha-naphthylamine.......... ... 4.0 Phenyl-beta-naphthylamine............ ... 4-+ Tolylentdiamines Metatolylenediamine........................ .. 3.0 Paratolylenediamine........................ .. 3.6 BIBLIOGRAPHY I. Hamilton, A.: Industrial Poisons in the United 8tates. New York, The Mac millan Co., 1925. The chapter on "Benzene Derivatives" has been drawn on freely in compiling the first part of this paper. VoLu N0.1 ler Intorikai. Btuttfut, ol. 2, p. 780. ion of Anflino Jour., 1020ookofOrganio' John Wiley : ilaylendiemin ( den Thieiir. Path. a. 1. Wiikung des Thierkflrper. Beititge inr ` id., 1883, 18, J.I.H. Much, IM1 ST08506I9 STUDIES ON EXPERIMENTAL PNEUMONOKONIOSIS. VI. INHA LATION OF ASBESTOS DUST: ITS EFFECT UPON PRIMARY TUBERCULOUS INFECTION {Concluded) Leroy U. Gardner and Donald E. Cummings From the Saranac Laboratory for the Study of Tvberculorie The Edward L. Trudeau Foundation, Saranac Lake, New York Primary Tuberculous Infection in Pulmonary Asbestosis To determine whether inhaled asbes tos dust affects the course of tubercu lous infection, the same procedures have been employed which were used in the previously reported experiments on other dusts, i.e., granite (2), marble (3), carborundum (4), and quartz (5). For this purpose animals exposed to asbestos dust have been infected by causing them to inhale small numbers of tubercle bacilli of the attenuated strain Ri> By this means, in undusted guinea-pigs a self-limited infection of the respiratory tract is produced with lesionB comparable with those of the "primary complex" in man. They consist of a variable number of small discrete subpleural tubercles in the lung, together with a more extensive involvement of the tracheobronchial lymph nodes. The pulmonary tubercles caseate and then the bacilli die. The caseous . matter is absorbed and after a period of from eighteen months to two years, complete resolution of the entire lesion takes place (8). Macroscopic disease of the spleen and liver is almost never seen. The course of the infec tion in such guinea-pigs is generally nonprogressive (Figs. 18, 19, and 20). During the period from 1920 to 1928, there were three instances of general ized tuberculosis among 251 guineapigs infected with this organism as controls to different dust experiments. In one of these three there was some question as to the identity of the animal. In the last three years, how ever, eleven instances of disseminated disease have been discovered among 148 controls similarly infected. The occurrence has been sporadic, and only one animal in a group of twentyfive or fifty such controls exhibited evidence of spreading disease. The cause of this apparent accentuation in virulence has not been ascertained. It is hard to believe that after main taining a constantly low degree of virulence for a period of thirty years the Ri strain has rather suddenly been altered. As far as is known, the gly cerin broth on which it has been culti vated has been prepared in the same manner as heretofore. The dosage used for inhalation infection has been maintained at a constant level. The only discoverable factor which has not 97 Vol. u No. 3 ST0850620 9S THE JOURNAL OF INDUSTRIAL HYGIENE been controlled is the guinea-pigs used for the experiments. They have regu- e introduction of epizootic pneumonia into the animal house. It had not been considered necessary to perform routine intracutaneous tuberculin Fio. 14.--Primary subpleural tubercle partially healed by fibrosis. Below it and to the left is a nodule oi hyperplastic lymphoid tissue. Slightly removed are foci of dust reaction. No spread because no contact between two lesions is estab lished. Exposed to both dust and infection 357 days. Approximately X20. Fio. 16.--Healed fibrous tuberculosis in an area of asbestosis. Simultaneous expo sure to dust and infection 838 days. Approx imately X45. Fig. 15.--Another primary subpleural tubercle from the same lung as Figure 14, which has spread locally into an area of dust reaction. Approximately X20. larly been purchased from one fanner. On their receipt they are quarantined for a period of three weeks to avoid the Fio. 17.--Section of uncomplicated as bestosis from same lung as Figure 16, show ing more fibrosis than usual. Connective tissue stain. Approximately X90. tests, as no case of accidental tubercu losis had ever been recognized among this stock. It is possible that these recent cases of apparent spread of the J. 1. H. March, 1SU ST085062 I REACTION TO INHALED ASBESTOS DUST 99 low virulent artificial tuberculous infection may have been due to previous accidental infection with a more viru- residence in the animal house. Subinoculation tests are now in progress in an attempt to determine the type of M 7 jj + t. I Ib&K llosifl in is expoApprox- vL __ ___ Fig. 18.--Inactive subpleural tubercle in undusted control animal; retrogression has commenced; 654 days after infection. Approximately XI10. Fiq. 20.--Healed subpleural tubercle 654 days after infection. Approximately X110. :ated as- 16, showinnective '9 :ubercu- Fio. 19.--Inactive subpleural tubercle k '"dusted control animal; retrogression has commenced; 654 days after infection. Approximately XI10. 1 among lent strain. Generalized tuberculosis, it these!1 -Vv^owever, has always made its appear- d of the!K'^Boe on^y a^ter many months of Fig. 21.--Partially healed tubercle in wall of large bronchus. Location atypical; 357 days. Approximately X130. tubercle bacillus responsible for this disturbing manifestation. But in spite of these occasional in stances of disseminated tuberculosis in MiroJh.,I1.B88.1f1l ' Vol, lj 'r' J.No. 1 ST0850622 100 THE JOURNAL OF INDUSTRIAL HYGIENE the control animals, this method of A second group of twelve guinea- testing the effect of inhaled dusts upon pigs, which had been exposed to asbes tuberculous infection is of value. The tos dust for a period of two years under great majority of the controls not the conditions described above, were 1 exposed to dust inhalation exhibit infected by the inhalation of an nonprogressive pulmonary tubercles approximately equivalent dose of R, which ultimately heal by resolution. tubercle bacilli. At the same time On the other hand, almost every twelve normal animals were infected animal similarly infected and exposed as controls. Both the previously to the inhalation of quartz dust dies dusted animals and the controls were of generalized tuberculosis, unless then set aside in the general animal premature death from epizootic pneu room to be allowed to live as long as monia, or other causes, supervenes. they would. This second test was In the asbestos dust experiment, two designed to demonstrate whether the groups of guinea-pigs were infected alterations in pulmonary anatomy with the attenuated Ri strain of and physiology produced by the in tubercle. bacilli.? One lot of sixty- haled dust would affect a tuberculous three normal animals were subjected to infection. inhalation infection, and four days later forty of them were placed in the dusting room where they have been Infection Coincident with Dust Inhalation kept under the conditions already Of the forty guinea-pigs originally described, until death occurred. The infected and placed in the dusting remaining twenty-three of this group chamber, thirty-one are now dead. were set aside in a normal atmosphere Seven were killed, and the remainder as controls to the infection. From have died of various causes: four i this experiment it was hoped that the of generalized tuberculosis, seventeen J effect of inhaled asbestos dust upon a with more or less extensive epizootic tuberculous infection might be deter pneumonia, and the rest from various mined. In the animals thus exposed, accidental causes. Nine are still alive asbestos particles would continue to and apparently well at the time of this ; enter the lungs during the period of report, two years and three months tubercle formation. If solution or after infection. Some evidence of : other chemical reaotion should occur, spread of the tuberculous process has ; these changes might conceivably affect been observed in ten animals; in six the activities of the tubercle bacilli. it has been confined to the lungs, 1 The method of infection has been described elsewhere (2). The dosage em ployed for the present infection consisted of six puffs from a DeVilbiss vaporiser containing a suspension of Ri tubercle bacilli. The water clear suspension was prepared by centrifugation and filtration through paper so that there were from ten to twenty isolated bacilli in each oil im mersion field. No clumps were present. The bacilli were grown on glycerin broth, the first group for eight days, the second for twenty-one days. while in the other four it involved the abdominal viscera as well. Pulmo nary cavity developed in four animals. In most of the cases an extension of the tuberculous infection had occurred at some time previous to death, and subsequent healing resulted in fibrosis of all the secondary lesions. In all the tuberculous animals, even those J. I. H. Much. 1931 ST0850623 REACTION TO INHALED ASBESTOS DUST 101 elve guinea- with generalised disease, the sed to asbes- tend to be fibrous rather than > years under ^HB&exudative in type, above, were the twenty-three infection con- tion of an -twenty are dead. One died after ; dose of R, days, of generalized chronic tuber- i same time ^^^Ht^enlosis with extensive disease in the rere infected ^^^Bfc^pleen, liver, and abdominal lymph previously ^^^B&feodes. The remaining nineteen suc- ontrols were ^^HB^oambed for other reasons. Twelve neral animal of pneumonia and the others from /e as long as ^HjHjfygrious accidental causes. By the id test was ^^^^K}44th day, the tuberculous lesions in whether the lungs had healed to such an extent ry anatomy all evidence of caseation had 1 by the in- ^^^^^^Rfcappeared. With the one exception tuberculous the other animals autopsied this time showed only minute nth Dust of scar tissue at the site of the ^^^^^^nner tubercles. In two cases there i healed fibrous tubercles of micro- gs originally dimension in the spleen, the dusting ^^^^K|The distribution of the primary now dead. ^^^^HEpberculous foci in the lungs of the ie remainder ^^^^^Bjjbestosis group is somewhat atypical; causes: four only are the usual subpleural is, seventeen ^^^^^Eberdes formed, but in addition not a ive epizootic ^^^^Hmr/ooi are found in the depths of the from various apparently originating in lym- are still alive tissues at bifurcation of the 2 time of this ^^^^Hgjponchial tree (Fig. 21). These pul- hree months ^^^^^^Epnary lesions are associated with the e vidence of ^^^^^Hmstomary lymphatic metastasis to the i process has ^^^^Hmcheobronchial lymph nodes, and the imals; in six ^^^^Bpvelopment of extensive disease in > the lungs, location. Many of the pulmo- involved the tubercles are independent of foci ell. Pulmo- ^^^^^Hfidust reaction and apparently when four animals. occurs, the normal process of tension of the ^^^^^^KpSOlution is free to proceed. Such 1 occurred at resolve completely, and ultimately death, and ^^^^Hwppear. Others are contiguous to or ed in fibrosis into areas of dust accumulated ions. In all respiratory bronchioles. When , even those ^^^^^^^ghoontact is established, a reaction much more marked than that produced by either irritant alone is the result. Extensive chronic inflammation and granulation tissue develop, but the dust cells do not migrate into the interior of the tubercle, as in the case of inhaled quartz. Nevertheless, the subsequent course of the tuberculous process is altered. In some instances there is merely an interference with the usual process of resolution, so that excessive fibrosis and calcification of the necrotic central areas result. In other cases,, some product is produced (possibly soluble silica) which causes renewed multiplication of the bacilli and a spread of the tuberculous process. The extension takes place locally about the primary foci of infection (Fig. 15), and there is also metastasis of tubercle bacilli to the peribronchio lar foci of dust reaction (Fig. 7). New tubercles develop in the latter location, which are temporarily progressive and which may even break down to form small cavities. Usually, however, the process tends to come to a standstill, and ultimate healing with fibrosis and considerable anatomic deformity is the result (Fig. 16). The spreading dis ease is usually confined to limited areas in the lung, and death has with but one exception occurred from other causes. Such endogenous reinfec tions have first been encountered 203 days after the beginning of the experi ment. The last animal of this group studied died on the 838th day, of endemic pneumonia which was strictly localized to one cephalic lobe. The lungs show no trace of subpleural primary foci of infection, but in the deeper portions along the course of the large bronchi are healed fibrous tuber- J. I. H. March, 1931 S T 0850624 102 THE JOURNAL OF INDUSTRIAL HYGIENE cles with plaques of bone and marrow spread in the preestablished scar tis elements in their centers. These have sue, and undergo extensive caseation. been interpreted as the remains of Early metastasis to the tracheobron primary tubercles produced by bacilli chial lymph nodes occurs and the most which did not reach the periphery at extensive foci of reaction are found in the time of infection because of the this location. In fact, in one guinea- obstructing dust in the bronchioles. pig dying of an acute pleurisy on Elsewhere about respiratory bronchi the twenty-eighth day no pulmonary oles are very massive circumscribed tubercles can be discovered, whereas foci of fibrosis containing the com the lymph nodes are heavily infiltrated pressed remains of gland-like air with masses of epithelioid cells. All spaces. Whether all of them were the animals dying on and after the once the site of specific tubercle cannot thirty-third day show veiy extensive be definitely determined. However, tuberculosis of the spleen and hepatio the occasional occurrence of concentric lymph. masses of scar tissue enclosing a few The infectious process exerts a very giant cells suggests, in some instances, noticeable effect upon the reaction to the presence of tubercles. In other the dust. In all but one of the ani organs, the tracheobronchial lymph mals the amount of fibrous tissue about nodes and abdominal viscera, there the respiratory bronchioles is much are also many non-caseous fibrous more marked than in non-tuberculous tubercles. animalB exposed for the same period. Injection Superimposed, upon an Established Asbestosis In two of them, which are uncompli cated bythe presence of epizootic pneu monia, the alveolar septums in wide Of the small group of twelve guinea- areas peripheral to the foci of localized pigs infected after two years' exposure dust are extremely thick and fibrous. to asbestos dust, six died and three It is of interest to note the effect of were killed during the following forty- the infectious process upon the asbes eight days. Three of those dying pre tosis body. The development of case sented an acute non-tuberculous pneu ation in an area of reaction containing monia involving only one lobe of the these structures ultimately destroys lung, and two, an acute hemorrhagic them. They lose their characteristic pleural effusion. golden-yellow color, fail to give a Pulmonary tubercles were first found Prussian blue reaction, and are appar in the fourth animal dying on the ently so completely disintegrated that thirty-third day; all of the remaining not even a supporting fiber remains. five showed some evidence of pulmo Polarized light fails to reveal refractile nary infection. The majority of the elements. In the walk of small tuber tubercles occurred not in the usual culous cavities developing in foci of subpleural zone of the lung, but in the dust reaction, the various steps in the areas where dust reaction had already destruction of the asbestosis body can been established. In some instances be studied. The cause of their dis there are also characteristic subpleural appearance has not been determined lesions. The peribronchiolar tubercles but it is possible that the change in j.lh. ; i scar tiscaseation. vcheobrond the most 1 e found in r ne guinea- ' eurisy on pulmonary } 1, whereas * infiltrated cells. All after the extenaivei ad hepatic] jrts a very] eaction tok )f the anissue aboutj i is much? uberculous 5 me period.^ uncompli-j ootic pneu-j oa in wide] if localised] ad fibrous!! ie effect on the asbes-j :nt of case-' containing y destroys' aracteristio* to give a are apparjrated that ;r remains.]] il refractile mall tuber-' in foci of! iteps in the' is body cahj : their dis^ determined] change in] j. i. H. March, lttl ] S T 0850625 REACTION TO INHALED ASBESTOS DUST 103 jjyjbogen ion concentration incident to caseation may favor solution of the foreign bodies. Discussion V The physical and chemical properties of asbestos are so unlike those of any other dust previously studied that, 'when inhaled, particles of this sub stance provoke an unusual type of otion in the lung. Localisation of Dust he fact that a fiber as long as 100 even 200 microns can be inhaled L ultimately reach the finer branches ?#ha bronchial tree is surprising and htroverts the accepted ideas of the fectfveness of the upper respiratory ttotective mechanism. Whether such ictores enter the lung in full exteni, or whether they are partially has not yet been determined. ; fibers do not occur in the dust , In any case, it is difficult to a structure of such dimension its way against the normal it of ciliary action. It is generr assumed that prolonged inhalation ftdust provokes a chronic bronchitis, lit in the case of asbestos dust no biologic evidence of such a change i been observed within a period of `and one-half years. It is quite dble that the physiologic activities the ciliated epithelium may be without demonstrable anachanges. In support of such a ris the fact that very long fibers ^ve not been discovered in the deeper one of the lung until the dust ation has been in progress for 1 months. ke other dusts, asbestos fibers Dt, at least for two years, pene trate into the ultimate divisions of the primary units of the lung; the major part of them come to rest in the respiratory bronchioles. It will be recalled that these structures are lined, not by ciliated, but by smooth cuboidal epithelium, and that at inter vals along their walls are the openings of a variable number of alveoli. As a result, the bronchial tube at this point is no longer smooth walled, but is very irregular in contour. This roughness, is probably at least one of the factors responsible for the arrest of the elon gated spicules and fibers which catch in the openings of the lateral alveoli. In marked contrast with this is the behavior of a particulate dust like quartz, the major portion of which passes through the lumen of a respira tory bronchiole and enters the alveolar duct and its further ramifications. Having come to rest, the asbestos particles are ingested by free alveolar phagocytes. As so much of the mate rial consists of elongated fibers, giant cells are very prone to develop. With in the cytoplasm of these cells the chemical changes responsible for the development of that unique structure, the asbestoBis body, occur. The proc ess requires a period of approximately two months before the characteristic alterations are produced. Chemical Reaction and Asbestosis Body That the changes in the inhaled material are truly chemical in nature is indicated by the appearance of dis solved iron in the cytoplasm of certain phagocytes at a time previous to the appearance of the asbestosis body. The presence of the iron imparts a diffuse yellow coloration to the cells ST 0850626 104 THE JOURNAL OF INDUSTRIAL HYGIENE and it reacts specifically with potas tosis bodies. He noted that they were sium fertocyanide and dilute hydro not digested by trypsin and that they chloric acid. contained less iron than chrysotile. As previously noted, study of the He also noted that they failed to cast a structure of the asbestos fibers indi characteristic pattern when treated by cates that iron occurs in intimate com the X-ray diffraction method of Bragg, bination with silica, and even in the though a central fiber could be demon best grade of chrysotile it actually strated with a dissecting microscope. replaoes some of the magnesium. He therefore concluded that they were Chemical changes involving one con fibers of vegetable origin covered with stituent of the asbestos molecule must colloidal aggregates of adsorbed blood affect its other components. The proteins. Stewart (14) replied to presence of iron uniformly distributed Cooke's suggestions, and stated that throughout the cytoplasm of a phago- all the reported cases of asbestosis had oyte may indicate either hydrolysis of exhibited these curious structures. the ingested dust or solution of at least Stewart (15) later noted that anti- part of the original constituents and a formin did not destroy them. Gloyne subsequent release of silica. This (16) stated that the asbestosis body silica may exist in any of several withstood calcination, but lost its physical states, as soluble, colloidal, golden-yellow sheath after treatment or insoluble silica, or as soluble silicate. with concentrated sulphuric acid, leav- By study of the chemical structure and ing a thin central fiber. He reported the method of formation of the asbes- the body as refractile on dark ground tosis body, it should be possible to illumination- ; discover the actual mechanism by We have been able to confirm many! whioh structural alteration of an in of these findings, and we have also at* j haled silicate occurs. tempted to prove conclusively whether j The asbestosis body has been sub or not the asbestosis body contains; jected to various chemical tests by organic matter. Since it resists cal- j several investigators. Cooke (9) and cination without change in configu- j McDonald (10) first described this ration or color, and since it is not unusual foreign body and stated that digested with either pepsin and hydro it did not stain with aniline dyes, but chloric acid or trypsin, it is not to be gave a marked iron reaction. They regarded as protein in nature. More also noted that it was not doubly over, asbestos fibers fail to adsorb retractile. McDonald (10) and Sim- proteins when placed in blood or pep son (11) also presented a theory for the tone broth media for several months. formation of the golden-yellow bodies This curious structure is not soluble in from asbestos. Stewart (12) claimed any of the usual organic solvents* and the presence of asbestosis bodies in fails to show charring with sulphuric histologic sections of lung as diagnostic of pulmonary asbestosis. Cooke (13) later called attention to the relation between the iron content of asbestos dust and the iron reaction of asbes ' It will be recalled that the asbestosis bodies and even their supporting fibers ultimately disappear in an area of tuber culous necrosis. The explanation is not entirely dear but solution may be due to a high degree of alkalinity created in tbs degenerated cells. J. I. s. March, 1S31 iey were j iat they] ry8otile.| o cast a] ated by! f BraggJ demon-,J roscope^ iey were] red wity d blc lied tol d that JIB lost it; eatmenf dd, leavj repor : ground l or pep mont oluble: jnts* an<| julpbu aabest ing fib or tub in is no 5 due to i ,d in tn J.I., M*rchi 1 ST 0850627 REACTION TO INHALED ASBESTOS DUST 105 add. Consequently, it is considered a. to be an inorganic structure. InasH much as a central fiber can be readily R demonstrated in nearly all instances, 57 {2ie body is undoubtedly derived from asbestos. . :<rhe marked iron reaotion of the ,/ asbestosis body is not to be confused S' with, that obtained on the dust preftvious to contact with the animal body, jin' its original state the iron in the _ is almost wholly in the ferrous Rate, while in the asbestosis body " ` feme iron can be detected. structure is therefore regarded |<an oxidation product of the original i an attempt to prove whether the 'h of the asbestosis body was already at in the fiber or whether it was 1 from animal tissues, the experi- at was made in which asbestos b, freed from iron by leaching with Dchloric acid, were injected into acutaneous tissues of guineas noted above. It was unsucbecause the acid treatment the asbestos soluble in the ' fluids, and no significant reaction One month after the injec- ft>,; practically no trace of the fibers I be discovered and only a very lit fibrosis marked the site, atment of asbestos fibers for the ation of free silica disclosed touease with which the chrysotile le oould be opened. If enzy- i action or hydrolysis of the fiber ed to take place in the presence 1 fluids, it is quite possible that Lferrous or ferric silicate existing in is oxidized and hydrolyzed to produce the asbestosis i'ftfr- ^ evidence that hydrolysis or partial solution of the inhaled dust is responsible for the development of the asbestosis body, the following obser vations may be cited. When studied by Bragg's X-ray technic, asbestos fibers exhibit a characteristic crystal line pattern which is lost upon treat ment with acid. Cooke (13), using the same method, showed that asbestosis bodies exhibit no crystalline structure. Ray and Ganguly (17) state that precipitates formed from solutions of ferric chloride and sodium silicates, which are identical in color with the asbestosis body, also yield no crystal line pattern by X-ray. As further evidence of physical alteration is the fact that the asbestos fiber is highly refractile in polarized light, whereas the asbestosis body has completely lost this property.* We have attempted to reproduce the 4 It has been assumed that the demon stration of iron in the outer coating of the asbestosis body is evidence of hydrolysis of the original asbestos fiber on which the body formed. But actually this finding does not constitute definite proof unless an endogenous source from blood pigment can be exoluded. We have thus far failed to eliminate this source of iron. However, the demonstration of magnesium in the asbestosis body would furnish equally convincing proof of hydrolysis ana the objection that it was derived from the tissues could hardly be raised, for the amount of this substanoe in the body is extremely small. An attempt has, there fore, been made to develop a microchemical test for magnesium. It has been found that both asbestos fibers and asbestosis bodies are definitely stained a light blue-$reen color when treated on mioroslides with a dilute hydrochloric acid solution of paranitro-benzene-azo-resorcinol followed by a bath of sodium hydroxide. The presence of magnesium in the outer layers of the asbestosis body is convincing proof of hydrolysis of the inhaled dust. This color reaotion is given only by magne sium, cobalt, and nickel, substances which do not occur in sufficient concentration in the tissues to cause reaction. Therefore, endogenous sources for the coating material of the asbestosis body are assumed to have been eliminated. ST 0850628 106 THE JOURNAL OF INDUSTRIAL HYGIENE asbestosis body from asbestos fibers by until finally the membrane becomes, j immersing them for prolonged periods impermeable. in buffer solutions of various hydrogen Microscopic structures of fibrous j ion concentrations, both above and character, suggesting aabestoais bodiesJ below neutrality. The solutions have have been produoed both with dilute! been adjusted with agar and silica gel solutions of an iron salt and a soluble.! to a visoosity near that of the cell. silicate, and with iron and silica solaj Oxidising agents have been added and (19). the reaction has been allowed to pro These observations lead us to con-j ceed in the incubator for six months. elude that the asbestosis body is a] No golden-yellow structures were derivative of the crystalline asbestos! obtained. fiber which has been oxidized and] We have, however, been able to hydrolyzed to a golden-yellow amor-J reproduce the structure of the asbes- phous structure. As such, it can tosis body quite closely by other regarded as the first direct evidence i means. Iron free asbestos fibers are altered chemical composition in impregnated with an iron salt by inhaled silicate dust. heating to dryness in a dilute ferric In the animal body, the evidenoe] chloride solution and ignited. The thus far accumulated would indicat fibers are then placed in a solution of that the lung of the guinea-pig and ofl sodium silicate. The iron salt adher man furnishes the most favorable en-1 ing to the fibers reacts rapidly with the vironment for the development of' silicate, producing a curiously shaped asbestosis body. Asbestos fibers trans-J golden-yellow structure which very ported from the lung to the trao closely resembles the aabestoais body bronchial lymph nodes do not or (Fig. 13, Nos. 1 and 2). appear to produce these structu A similar reaction is involved in the Possiblyprolonged residence in the lu production of the familiar phenome has deprived them of their capacity for] non, the "silicate garden" (18). If a further reaction, or possibly some crystal of ferric chloride is added to a necessary factor is lacking in thej solution of sodium silicate, golden- lymph nodes. It is believed that thei yellow filaments, often several inches few asbestosis bodies found in the; in length, rapidly develop, which exhibit irregular swellings and buds. Ferric silicate iB probably formed. This product is partially hydrolyzed, producing a thin wrinkled skin of silicic acid streaked with ferric hydroxide. This skin, acting as a semipermeable membrane, permits diffusion to take place and a high osmotic pressure develops with a consequent rupture of the membrane. Further hydrolysis nodes were transported after attaining! full development in the pulmonaryj air spaces. Injection of asbestos du into the peritoneal cavity of guine pigs has failed to produce characteristic] structures in any quantity. In the subcutaneous tissues they do develop,| but the period of incubation is nearly twice as long as that required in thj lung. Practically no asbestosis bodiei have formed in the lungs of rabbits and albino rats. The necessary environ! occurs and the reaction repeats itself mental factors which are lacking in j. i.fij Hatch. 1# le become*.] of fibrou joaifl bodie with dilut d a soluble 1 silica sob us to oon^ body is ne asbest ddized and illow amoj i, it can evidence o .tion in ae evideno lid indjcat i-pig and ivorable ment of fibers tr the tra otor structu in the In capacity fo 3sibly ing in zed that und in tb ter att pulmon isbestoa du Y of guine :haract ity. In do develop ion is ne uired in istosis bodlf f rabbits i ary enviroj e lacking -I S T 0850629 REACTION TO INHALED ASBESTOS DUST 107 of these situations are entirely not sufficient for the production of _aown. Lttempts to determine whether the body will develop in the asbestosis bodies. Pulmonary Fibrosis when any of the theoretically That the long-continued inhalation elements are lacking have of asbestos dust is responsible for the i far met with little success. The development of pulmonary fibrosis is lents n vitro indicate that now unquestioned. From many parts atalline ferric or ferrous silicate in of the world come radiographic reports j,medium of proper viscosity and a of fine fibrosis in the lungs of persons r for support are probably essential exposed by occupation to the inhala >\the production of these structures. tion of this substance. The findings Lour attempt to determine whether from at least ten postmortem examina t\derived from the tissues could be tions have furnished reliable evidence ituted for the iron inherent in that the shadows seen in the roentgeno j .ohrysotile molecule, we have been gram are produced by areas of fibrous jfeated by the fact that the manipula- tissue (20). In guinea-pig experi ineoesaary to remove the iron from ments reported in this paper, it has ij,fiber apparently renders that been shown that the fibrosis begins in i soluble in the body fluids. those portions of the lung where the I injection and the inhalation of dust is localized, and that this reaction -Barre granite dust, which con- can be detected in X-ray pictures after i -both free silica and iron, have about two years' exposure to the con er.'i'resulted in the formation of centration of dust used (Fig. 3). gfftures in any way suggesting The earliest evidence of proliferation bodies. The solution of of fibroblasts has been encountered be demonstrated by micro- approximately 500 days after the tests and it generally is commencement of the dust exposure. ied that the silica is also ulti- It first appears in the immediate dissolved. Intraperitoneal in- vicinity of the largest accumulations i of granite from Lorain County, of dust cells, which occur in the 9, have been made because this ma il'contains iron in the unusual form Mrous carbonate. No suggestion asbestosis body ban been dia ls the light of subsequent fijsjit iB now recognized that the sum is not a proper location for "^ test, and subcutaneous inoculaljbave already been made with this ape, but it is too early to report respiratory bronchiole and its adjacent alveoli. As increasing amounts of dust accumulate in the walls of these structures, the amount of fibrosis is likewise increased. In the otherwise normal guinea-pig, migration of dust cells to intrapulmonary lymphoid tis sue has not been encountered, and in consequence the nodular foci of fibro sis, which are so characteristic of the reaction to quartz dust, fail to develop. i,-far, it would appear that the nee of iron and free silica is The occurrence, in one of the last animals killed, of a more diffuse fibrosis peripheral to the point of ST 0850630 108 THE JOURNAL OF INDUSTRIAL HYGIENE maximum dust deposition suggests more slowly than asbestos in the that collapse induration incident to guinea-pig. After 910 days, the maxi occlusion of respiratory bronchioles mum period of experimental exposure may play an important part in the later to granite, the lungs showv large stages of the disease process. masses of dust filled phagocytes lying Asbestos dust, a silicate of magne in the lumen of the alveoli along the sium, is relatively soluble in fluids com alveolar ducts and atria. In the parable with those of the tissues. The adjacent septums there is a slight asbestosis body develops only after thickening due to the presence of solution has occurred in the proper lymphoid and monocytic cells, but environment. The development of fibrosis is entirely lacking. The sig. these structures in the lungs of guinea- nificant feature is the absence of dust pigs and of human beings is the first particles in the connective tissues of tht direct evidence of solubility of an lung. In the tracheobronchial lymph inhaled dust known to produce pul nodes, on the other hand, dust accumu monary fibrosis. It still remains to be lates in such quantities that fibrosis demonstrated whether a dissolved sub- develops within one year, and aftei stanoe is the factor responsible for the two years' exposure the lymphoic multiplication of fibroblasts in pneu- tissues are largely destroyed by i monokoniosis. In this connection the Beries of true silicotic nodules. It ha evidenoe from asbestos inhalation in been postulated that fibrosis has no: the rabbit should prove most valuable. developed in the lung of the If, after a proper period of exposure, exposed to granite because the dus typical asbestosis bodies should still particles do not come into sufficiently be lacking, and if fibrosis should like intimate contact with the fibroblast' wise fail to develop, it would be logical of the alveolar walls. In the lympl to oonclude that fibroblasts were not nodes, on the other hand, fibrosi stimulated because no solution of the begins early, and typical silicoti dust had occurred. Thus far, the nodules are produced because heavy reaction of the rabbit has only been concentrations of dust are brought int studied during an exposure period of close proximity with connective tissu 330 days. The only sign of asbestosis elements. body formation is an irregular swelling The conditions of the experiment of certain fibers which give micro with granite and asbestos dusts woul chemical tests for iron; evidence of theoretically favor a greater reaction i fibrosis is entirely lacking. The 500- the former case. The concentration t day period of exposure, when true granite dust was over eight times e fibrosis appeared in the guinea-pig, great as that of asbestos (287,700,00 is anxiously awaited. particles less than 1.5 microns i Comparison between Reactions to Asbestos and to Other Dusts diameter per cubic foot of air fc granite and only 34,486,000 particlt of the same size for asbestos). Ho? Granite dust, which is known to pro ever, the greater solubility of maj voke the formation of extensive fibro nesium silicate, together with i sis in human beings, appears to act peculiar localization, probably is tl j.i. Much, 1! x)s in the] 3, the maxi-l al exposure] how la cytes Iyii i along the] i. In the] is a slight iresence of] cells, but] The sig-J tnce of du agues of :hial lymph ist accumu hat fibr and aft lymphoid >ved by les. It sis ha* not the ar e the di sufficient fibroblast the lymp id, fibr al silicot ause heav rought int ctive tis ixperimenti lusts wou r reaction i entration ( ht times 287,700,0 microns of air fo JO particle os). Hoy ;y of with itj ably is S T 0 8 5063 REACTION TO INHALED ASBESTOS DUST 109 responsible for the production of carborundum does excite fibrosis, and imore rapid and extensive pulmo- structures suggesting silicotic nodules ; fibrosis by asbestos dust. have been discovered. As in the case which is generally accepted of granite, proliferation of fibroblasts ' most active of all the nontoxic occurs at the point where they are i which are inhaled in industry, is in intimate contact with sufficient Soh less easily dissolved than Babes numbers of dust laden phagocytes. ia and yet it will produce extensive Whether solution of carborundum by In the lungs of experimental the body fluids is possible has never i more rapidly. In guinea-pigs, been determined. fibrosis, and even necrosis, From these observations on the Ifbeen observed after one year's reaction to various types of dust, an to quarts dust; in rabbits, hypothesis has been developed that silicotic nodules are formed in fibroblasts proliferate in response to months. The difference in sufficient concentrations of a soluble ate of reaction to quartz and substance liberated by the action has been ascribed to several of the phagocytes on the included With equivalent concentra- dust particles. The soluble substance tt of dust in two given atmospheres, probably diffuses through the mem quartz than asbestos particles brane of the intact phagocytes, but it Jibe inhaled and reach the paren- is only stimulating to fibroblasts in of the lung. This is presum- the immediate vicinity. The unde adue to the relative differences in fined soluble substance, possibly silica bape and the surface characteris- in some form, is rapidly neutralized f'the particles. After phago- after leaving the cells in which it is i,`quartz particles seem to pos- produced, and it exerts no effect upon Fjthe ability to stimulate a rapid more remote connective tissue ele "Ion of the dust cells, so that they ments. The process of neutralization citrate large masses of dust about may be chemical in nature or it may be of intrapulmonary lymphoid a result of absorption by some other s;s Here again, but by a different type of cell which is itself unaffected. the foreign bodies are l in circumscribed areas. Subatly, perhaps as the result of Theoretical Consideration of Pneumonokoniosis on of the quartz, a local pro- In a previous paper dealing largely on of fibroblasts takes place, with the reactions to granite and orundum dust has produced no carborundum dusts (21), it was sug fibrosis after exposure as gested that the primary lesion of pneu _as three or four years. In the monokoniosis consists in the develop It is treated much like granite ment of an obstructive fibrosis in ^ collected in phagocytes which the tracheobronchial lymph nodes within the air spaces, so that attended by stasis in the afferent Eist cells establish no contact with lymphatics in the lung, and ultimately Jerlying connective tissue. In followed by a perilymphatic fibrosis. oeobronchial lymph nodes, When only these two types of dust had ST0850632 110 THE JOURNAL OF INDUSTRIAL HYGIENE been studied, such an hypothesis to the asbestos dust cells, but for causes looked tempting, for the only trace of inherent in themselves, they do not fibrosis in the lung in these cases was migrate to these vessels. situated about the large lymph trunks. Masses of dust filled phagocytes lay Tuberculous Infection and Asbestosis for many months in the air spaces, and Where inhalation infection is insti apparently provoked not the slightest tuted simultaneously with commence reaction of the connective tissues. ment of dust exposures, the majority But subsequent experimental investi of inhaled tubercle bacilli localize in gation has modified this concept; it is small peripheral lymphoid masses in a now believed that fibrosis develops zone immediately beneath the pleura. wherever sufficient amounts of dust of This is characteristic of such infection the proper type come into intimate with the organism used in the experi contact with fibroblasts. The pri ment. A certain number come to mary obstructive lesion in the tracheo rest atypically in the deeper lymphoid, bronchial lymph nodes occurs with tissues along the intermediate bronchi, quartz inhalations but not with asbes possibly because they are mechanically tos. Undoubtedly such a lesion has arrested by inhaled dust particles. tens the development of reaction in The majority of the tubercles formed the lung, for it reduces elimination and undergo spontaneous resolution which concentrates the dust, but it is not is the outcome of the infection in essential to the production of pulmo most normal control animals. A cer nary fibrosis. tain number of tubercles by accident One further point in connection with localize in proximity to foci of localized the state of the lymphatics deserves dust. If the contact is sufficiently comment. In experimental aabesto- intimate, these tubercles spread locally sis, both in the guinearpig and in the and more remotely into foci of dust rabbit, the lymph vessels are widely reaction about respiratory bronchioles. dilated after as short an exposure as A new crop of tubercles develop in from thirty to sixty days. Inhaled this location, and these may progress asbestos dust is not transported to the and even form small cavities, but the tracheobronchial lymph nodes in any ultimate outcome is usually healing considerable quantity, and no obstruc with more or less extensive fibrosis tive lesion has been produced at this and calcification. The tuberculous time. Therefore in this case the dila process is practically never generalized tation of these vessels must have some throughout the lung, but is generally other cause; possibly it is merely a confined to small nodular foci. Blood physiologic response to intrapulmo- stream metastasis is usual and macro nary irritation. Asbestos filled phago scopic disease in the spleen and some cytes do not enter these channels be times in the liver is common, an occur cause they are apparently relatively rence almost never found in infection inactive, but epithelioid cells contain controls. In the thirty-one animals of ing tubercle bacilli may leave the lung this group dead at the time of this in great numbers. Apparently the report, a spread of the tuberculous lymphatic channel of escape is open infection occurred in 32.2 per cent. In J.I.H. U, 1831 ST0850633 REACTION TO INHALED ASBESTOS DUST 111 'per cent, of them, the tuberculosis effect upon tubercle bacilli of attenu subsequently more or less com- ated virulence. To exert this effect, ietely healed by fibrosis. It seems the dust and the tubercle bacilli must hbable that in the remaining mem- be brought into rather intimate asso - of the group a similar result would ciation. This occasionally occurred , been attained had they not died when the infection and the onset of the aturely from accidental causes. dust inhalation were simultaneous; `Where inhalation infection was it was much more common where infec perimposed upon a well-established tion was superimposed upon an already ibestosis of approximately two years' established asbestosis. The dust, per nding, the primary localisation of haps by the action of its dissolved prod a'.fcubercles was atypical. Many of ucts or by alteration in tissue reac ['tubercle bacilli were mechanically tion, initiates a renewed proliferation l up by the reaction to the dust in of the tubercle bacilli, and the infec respiratory bronchioles. It would tion spreads. But this stimulating that many, perhaps the major- effect is only temporary and ulti fiof these organisms were phago- mately the foci of new disease tend to and carried directly into heal by fibrosis. In this respect, distended lymphatic trunks. The inhaled asbestos dust differs from manifestation of tubercle for- quarts, which incites continued and on occurred not in the lung, but progressive multiplication of the bac the tracheobronchial lymph nodes, teria and consequent spread of disease. rndition which has never before As has been observed with the other observed in experimental inhala- types of dust (granite and carborun fection. Some organisms local- dum), the presence of asbestos in the tin the foci of duBt reaction and lung of an animal infected with ^produced tubercles; a certain tubercle bacilli promotes more exten of bacilli passed to the periph- sive fibrosis than is produced when twhere typical subpleural lesions either the organism or the dust is oped. The major portion of the acting alone. Where the two irritants -pigs comprising this group died are concentrated in the same area, .ere killed during a period of forty- each provokes the formation of granu days after infection. Within lation tissue which ultimately organ time not much extension of the izes to form fibrosis. But even in Bpulmonary infection had occurred, areas of dust reaction remote from the tracheobronchial lymph nodes site of tubercle, the fibrosis is excessive, heavily involved in all animals an effect for which explanation is lack after the thirty-third day. It is ing. (Figs. 15 and 16.) yearly to state what will be the *te outcome of infection super- Summabt upon a preestablished asbes- Guinea-pigB have been exposed for eight hours daily for periods as long as w these experiments, it would two and one-third years to an atmos that inhaled asbestos dust is phere containing approximately thirty- f exerting some stimulating five million particles per cubic foot of ST0850634 112 THE JOURNAL OF INDUSTRIAL HYGIENE asbestos dust (Canadian chrysotile) 1.5 microns and less in diameter. Rabbits and albino rats have likewise been exposed for shorter periods (330 days). The experiments demonstrate that fibrous structures at least as long as 200 microns can pass the protective mechanism of the upper respiratory tract and enter the lung. Anatomic evidence of injury to this mechanism is wanting. Inhaled asbestos dust does not penetrate to the terminal alveoli of the lung as is the case with a particu late substance such as quarts. The major portion is held up in the respira tory bronchioles. There phagocytosis takes place, and there the material remains localised, at least for a period of two and one-third years. Phago cytes containing asbestos particles migrate into the lateral alveoli given off from the walls of the bronchioles, and considerable numbers ultimately penetrate the adjacent connective tissues. In the guinea-pig, transpor tation of dust particles to intrapulmonary and mediastinal lymphoid tissues is so slow that changes in these struc tures play little part in the early development of asbestosis. In the rabbit, dust cells begin to appear in the lymphoid tissues of the lung within sixty days after the commencement of the inhalation; thereafter, they con tinue to migrate in increasing numbers. In the guinea-pig, fibrosis in the walls of the respiratory bronchioles and their lateral alveoli is first manifested after 500 days' exposure. Thereafter this type of reaction progressively increases in intensity and extent. The resulting atelectasis is responsible for a gland-like appearance, which is due to the contraction of the included alveoli and a consequent compression of the epithelial lining cells. In the rabbit sufficient time has not yet elapsed for fibrosis to be expected. In the lungs of guinea-pigs, asbes tosis bodies, apparently identical with those described in the human being, have developed after an exposure of approximately seventy days. In the' rabbit these structures have not been discovered after exposures as long as 330 days. In the albino rat they an very rare. Only two small typical forms have been discovered in one animal exposed for seventy days. The prevalence of chronic infections of the lung in all members of this series is possibly responsible. Asbestosis bodies apparently fail to form in the tracheobronchial lymph nodes of guinea-pigs. They may be transported in small numbers to these tissues and to areas of chronic pleurisy They have not been discovered in peritoneal cavity 100 dayB after inj tion of dust. In the subcutaneous sue of the groin, typical forms were found 102 days after the injection of 3 mg. of dust. Asbestosis bodies are not present in asbestos dust previous to contact with animal tissues. They are produced hy oxidation and hydrolysis of the chryBOtile molecule. The formation of these structures is the first direct evident that the body is capable of effecting changes in inhaled silicate particle The chemical processes involved have been discussed in exienso. Attempts at artificial production of asbestosis bodies in vitro have been partially suck cessful; solutions of ferric chloride an sodium silicate have been made to bine in the presence of a fiber to p~ J.L Hut*. the included! compression jells. In th^ has not yefl apected. v-pigs, ash dentical wit luman i exposure lays. In ave not es as long rat they small typic rered in on y days, eotions of this series j-ently fail, nchial lymp rhey may ibers to the -onic pleu overed in ys after inje^ cutaneous tj d forms we e injection) not present^ i contact e produced] of the cl iation of the irect evide le of efiectii sate partidg involved so. Attemp of asbe i partially i c chloride: i made to' a fiber to j.l Utnh. ST0850635 REACTION TO INHALED ASBESTOS DOST 113 T^ce more or less typical forms. The been reached after inhalation infection ' asbestosis body is therefore analogous with attenuated tubercle bacilli (strain ? to the well-known "silicate garden." Ri). In normal guinea-pigs such in ^Attempts to produce asbestosis bodies fection produces tubercles in the lung vivo by the injection of dusts con- and tracheobronchial lymph nodes staining iron salts and silicates have comparable to the "primary complex" ' bus far failed. The failure to produce in man. The lesions caseste and the t in tissues other than the lung and pulmonary foci heal by resolution. ^subcutaneous tissues of guinea-pigs Spread of the infection with macro [ man has not been explained. scopic disease in other viscera is very ' Comparison between the localization rare. In the asbestos experiment, one . the reaction to asbestos and other group of guinea-pigs was infected at i of inhaled dusts has been shown, the outset of dust inhalation; a second points at which inhaled dust is group, two years after the commence in the lung or lymph nodes ment of dust exposure. In the first with the type of dust. Granite Beries, 32.2 per cent, of the *nimala within the pulmonary air showed some evidence of spreading and produces no local reaction tuberculosis. New disease began as a Mibioblasts for several years. In the local extension from primary tubercles obronchial lymph nodes charac- and metastasis to areas where dust ) silicotic nodules develop within reaction had occurred was common. years. Carborundum likewise has Rarely small cavities developed in the to affect the stroma of the lung secondary foci. The tendency to heal i ln four years, but fibrosis in the ing by fibrosis was marked; at autopsy ph nodes has been observed. 40 per cent, of the cases showed healed Ugtz is rapidly concentrated by fibrous tuberculosis; macroscopic dis grating phagocytes in the pulmo- ease in the spleen and sometimes in the r and mediastinal lymphoid tissues, liver was common. The contrast with hese places it provokes an early animals similarly infected but exposed rapid multiplication of fibroblasts, to quartz dust is marked. In them as it is inhaled, is concen- every exposure longer than five months in respiratory bronchioles and resulted in generalized chronic tubercu jrlateral alveoli. Phagocytes cany losis of the lungs and other viscera. . Q,to the walls, where fibroblasts For the second asbestosis group l stimulated. infected, the localization of tubercles nph Btasis plays little part in was atypical. Many bacilli were f` asbestosis; the structure of this trapped in foci of dust reaction. Some intends to localize it within the produced local tubercles; others imme from the start. Lymph vessels diately entered the dilated lymph ves | dilated in the absence of detectable sels and were transported to the lotion. The dilatation may be a tracheobronchial lymph nodes. Tu -result of pulmonary irritation, berculosis in these nodes sometimes tuberculous infection is in- occurred without involvement of the only to a limited degree by lung. Early disease in the spleen and >d asbestos. This conclusion has hepatic lymph nodes was the rule. ST0850636 114 THE JOURNAL OF INDUSTRIAL HYGIENE The uitim&te outcome of infection in this group has not yet been observed. The combined action of asbestos dust and tubercle bacilli in the lung produced more fibrosis than did either agent acting independently. BIBLIOGRAPHY 1. Anderson, H. V., and Clare, G. L.: Applio&tion of X-Rays in the Glassi fication of Fibrous Silicate Minerals Commonly Termed Asbestos. In dust. and Engin. Chem., 1920, tl, 924. 2. Gardner, L. U.: Studies on the Rela tion of Mineral Dusts to Tuberculosis. I. The Relatively Early Lesions in Experimental Pneumokoniosis Pro duced by Granite Inhalation and their Influence on Pulmonary Tuberoulosis. Am. Rev. Tuberc., 1920-1921, 4, 734. 3. Gardner, L. U., and Dworskx, M.: 7dm. II. The Relatively Early Le sions Produced by the Inhalation of Marble DuBt and their Influence on Pulmonary Tuberculosis. Ibid., 19221923, 6, 782. 4. Gardner, L.U.: Idem. III. The Rela tively Early Lesions in Experimental Pneumokoniosis Produced by Car borundum Inhalation and their In fluence on Pulmonary Tuberculosis. Ibid., 1923, 7, 344. 5. Gardner, L. U.: Studies on Experi mental Pneumonokoniosis. V. The Reactivation of Healing Primary Tu bercles in the Lung by the Inhalation of Quartz, Granite and Carborun dum Dusts. Ibid., 1929, SO, 833. 8. Stewart, M. J., and Haddow, A. C.: Demonstration of the Peculiar Bodies of Pulmonary Asbestosis ("Ashestosis Bodies") in Material Obtained by Lung Puncture and in the Sputum. Jour. Path, and Bacterid., 1929, SS, 172. 7. Cunnings, D. E.: Studies on Experi mental Pneumonokoniosis. IV. The Separation of Particulate Matter Smaller than Screen Sizes into Graded Fractions. This Jour., 1929, 11, 245. 8. Gardner, L. U.: Healing by Resolution in Experimental Pulmonary Tuber culosis. Am. Rev. Tuberc., 19221923, 6, 163. 1.1.H. Kirch, UU "g derj Arch.l ajJ Physio-l impera-j 5- Pub.l ST0850S37 SUBJECT INDEX TO VOLUME XIII ';Thi* is a subject index to all the reading matter in the Journaloe Industrial Hygiene, jfone should, therefore, look for the subject word, with the following exception: "Book felloes" are indexedunder this title onpage363. The name of the author follows the subject in parenthesis. far author index, see page 364. r*o urn industry, dust hazard in r^Clark)............................................... 343 t conditions, working capacity of coal miners in relation to (Bedford |^,*nd Warner)...................................... 262 lometer for measuring cooling ower (Weeks)................................ 261 , temperatures, reduction of %_edford and Warner)................... 135 Sbmtos dust, effeot on primary tuVberculous infection (Gardner and ^jCununings).................................. 65, 67 rorkers, method of staining asbestoj sis bodies in sputum of(Gloyne).. 85 ^besyosis bodies in sputum of asj,-Jjestos workers, method of staining i (Gloyne).......................................... 85 SOBPBKre, tee Air. kiene derivatives and related com. pounds, toxicity of (8myth)......... 87 upon, determination of, in air , (Smyth)............................................. 227 jot pressure, high, in industry 61e of punctate basophilia in control i-of plumbism (Lanej........................ 276 bbs' dermatitis (Schwartz)....... 233 5/lncxb, carcinogenic potency of mini; eral oils (Twort and Twort)......... 204 ?Abbon Monoxide, production of, from paint in sealed compartments jy (Dudding, Dudley, ana Frederick)................................................... 333 3audiovascular impairment among negro factory workers (Allen)___ 164 iiNic, dental, night, in Montreal (Ward and Pedley)...........................289 oal miner, tee Miner, coal. Oolometer for measuring cooling power (Weeks)................................ 261 Yanids rash (von Bernewitz)............ 115 raaa Dust retention, factors involved in (Brown)............................................ 263 Dtbmbnobbhea among female clerks at Home Office of Metropolitan Life Insurance Company(Ewing).......... 244 Electric injuries, importance of points of contact in (Langworthy and Kouwenhoven)................................. 145 injuries produced by discharge of im- Sulae generator (Langworthy and iouwenhoven)................................ 326 Employment "sickness and death rates" (Stevens).............................. 66 Factory workers, negro, cardiovascu lar impairment in (Allen).............. 164 workers, negro, physical impairment in (Allen)......................................... 167 Fatioue in industry, subjective side (Hersey)......................................... 185 Fumes, retention of, factors involved in (Brown)............................................ 293 Generator, impulse, injuries produced by discharge of (Langworthy and Kouwenhoven)................................ 326 Health, U. S. National Institute of (Cumming)....................................... 1 Heat cramps, treatment and preven tion witn sodium chloride (Glover). 347 Hypertension, tee Blood pressure, high. Imfinger unit for determining Bulphur dioxide (Smith and Friis)................ 338 International silicosis conference, Johannesburg, 1930 (Badham)....... 169 Kata-Tbermometer, use of, as ane mometer (Bedford and Warner)... 4 bntal clinic, night, in Montreal (Ward and Pedley)...........................289 ubt, asbestos, effect of, on primary tuberculous infection (Gardner and Cummings)............................ 65, 97 hazard in abrasive industry (Clark). 343 rational method for calculating rec ords obtained with Owens' counter (Kagan and Broumstein)............... 10 retention, concentrations below 50 mg. per cubic meter (Brown)......... 285 Lead, colorimetrio detection and esti mation of (Krans and Ficklen).. . 140 poisoning, rfile of punctate basophilia in control of (Lane)....................... 270 Linseed dermatitis (Barnes)................ 49 Lunos, coal miners'............................... 19 Methyl Chloride, toxicity of (White and Somers)............................ 273 Mine air temperatures, reduction of (Bedford and Warner).................... 135 381 40 S T0850638 382 THE JOURNAL OF INDUSTRIAL HYGIENE MOB Mi neb, coal, radiographic study of in dustrially healthy South Wales coal miner*........................................ 10 coal, working capacity of, in relation to atmospheric conditions (Bedford and Warner)..................................... 262 Mineral oil, sea Oil, mineral. National Institute of Health of U. S. Publio Health Service (Cummins). 1 Negro factory workers, cardiovascular impairment in (Allen).................... 164 factory workers, physical impairment in (Allen).......................................... 167 Oil, mineral, carcinogenic potency of (Twort and Twort)......................... 204 Paint, production of carbon monoxide from, in sealed compartments (Dudding, Dudley, and Frederick). 333 Physical impairment among negro factory workers (Allen).................. 167 Radioactive Substances, dangers in refining (Schlundt, McGavock, and Brown).............................................. 117 United States Public Health Service, National Institute of Bashh of (Cumming).......................................... j Work capacity of coal mi--* io rda- tion to atmospheric teeStaoes (Bedford and Warner)____________ 2S2 ST 0850639 SUBJECT INDEX 383 BOOK NOTICES r*oi ijdental injuries (Kessler)....... 331 Kessler, H. H.: Accidental Injuries. Sexander, F., end Staub, H.: The The Medico-Legal Aspects of the Judge, end the Pub- Workmen's Compensation and 144 Public Liability.................................. 331 entary tract, protozoan parasitism Lynch, K. M.: Protozoan Parasitism of (Lynch)............................................. 83 the Alimentary Tract. Pathology, :en, * By Walker, J. H.: Heat- Diagnosis and Treatment.................. 83 ng and Ventilation............................ 331 Mental hygiene in industry (Elkind).. 231 npel, K. E., see Strecker, E. A. Microanalysis, quantitative organic (rnnspheres, mine (Payman and Sta- (Pregl).................................................. 116 Ltham).................................. ............ 266 Mind, human, view of, and how it works Jieiina, E.: Internationale Ubersicht (Strecker and Appel)......................... 144 raber Qeverbekrankheiten nach den Mine atmospheres (Payman and Sta- Beriohten der Gewerbeaufsichtsbe- tham).................................................... 266 hflrden der Kulturl&nder fiber die Nurses, personal hygiene for (Egbert) jfoip 1920 bis 1926 ............................... 45 84, 232 iMnai, judge, and public (Alexander Oberteuffer, D., see Williams, J. F. Sditaub).......................................... 144 Occupation and health, encyclopedia '''e,J. B.: A Textbook of Hygiene. 82 (vol. 1)....................................................292 ie prevention in community (Hil- Payman, W., and Statham, I. C. F.: i).................................................... 144 Mine Atmospheres............................. 266 es, contagious, manual of (Stim- Pregl, F.: Quantitative Organic Micro- srt, , S.: Personal Hygiene for tyrses-.......................................... 84, 232 ' ' H. B.: Preventive Manage- Mental Hygiene in Indus- ..................... 231 epey, treatment of (Talbot).... 84, 232 y, F and Zeraik, F.: Schidliche kse: Dftmpfe, Nebel, Rauch- und Jtaubarten.............................................292 qbd analysis (Woodman).................... 231 analysis................................................ 116 Protozoan parasitism of alimentary tract (Lynch)........................................ 83 Quinine in general practice (Johannessohn)..................................................... 144 Schools, industrial hygiene for (Wil liams and Oberteuffer)...................... 82 Silicosis, records of international con ference held at Johannesburg, 1930... 183 Statham, I. C. F., see Payman, W. ' 8chAdliche Gase: D&mpfe, Nebel. Staub, H., see Alexander, F. uch- und Staubarten (Flury and Stimson, P. M.: A Manual of the Com IZernik)................................................. 292 mon Contagious Diseases.................... 84 lealth, occupation and, encyclopedia Strecker, E. A., and Appel, K. E.: Dis Tvori).......................... 292 covering Ourselves. A View of the 1th, personal and community (Tur- Human Mind and How It Works....... 144 ...................................................... 82 Talbot, F. B.: Treatment of Epilepsy lasting and ventilation (Allen and 84, 232 frWdJcer)................................................ 331 rd, C. M.: The Prevention of Dis- Jgase in the Community..................... 144 lygiene, personal, for nurses (Egbert) , 84, 232 dene, textbook of (Currie)............. 82 ^-mistrial diseases, international re- pview of. 1920-1926 (Brezina)............ 45 ittluatrial hygiene for schools (Williams pand Oberteuffer)................................. 82 *ijtiries, accidental (Kessler).................331 iternational conference on silicosis, Johannesburg, 1930, records of......... 183 Turner, C. E.: Personal and Commu nity Health.......................................... 82 Unemployment, case Btudies of........... 144 Ventilation, heating and (Allen and Walker)................................................ 331 Walker, J. H., see Allen, J. R. Williams, J. F., and Oberteuffer, D.: Industrial Hygiene for Schools......... 82 Woodman, A. G.: Food Analysis. Typical Methods and the Inter pretation of Results........................... 231 Workmen's Compensation for acciden Bhannessohn, F.: Cninin in der Allge- tal injuries (Kessler)............................ 331 T&einpraxis........................................... 144 Zernik, F-, see Flury, F. H12- ST0850640 AUTHOR INDEX TO VOLUME XIII Allen, F. P.: Cardiovascular Impair ment among One Thousand Negro Factory Worker*................................ 164 Allen, F. P.: Physical Impairment among One Thousand Negro Factory Worker*............................................... 167 MSI Ewing, R. E.: A Study of Dysmenor rhea at the Home Offioe of the Metro politan Life Insurance Company___244 Ficklen, J. B., see Kraus, E. W. Folliott, E., see Brownlee, A. Frederick, R. C., see Dudding, J. S. Friis, B. 8. T., ses Smith, R. B. ia Conference Held at Johannesburg, August, 1830....................................... 168 Barnes, M. H.: Linseed Dermatitis___ 49 BedforcLT., and Warner, C. O.: The Kata-Thermometer as an Anemo meter ................................................... 4 Bedford, T., and Warner, C. G.: Obser vations on the Working Capacity of Coal Miner* in Relation to Atmos pheric Conditions..................................252 Bedford, T., and Warner, C. G.: The Reduotion of Mine Air Temperatures. 136 Broumstein.W., see Kagan, M. Brown. C. .: Quantitative Measure ments of the Inhalation, Retention, and Exhalation of Dusts and Fumes by Man: II. Concentrations below 60 Mg. per Cubio Meter.....................285 Brown, C. E.: Studies in Dust Reten tion: III. Factors Involved in the Retention of Inhaled Dusts and Fumes by Man.....................................283 Brown. M., see Schlundt, H. Brownlee, A~ Folliott, E.. Gilchrist, J. C., and Hiley, R. M.: Coal Miner*' Lung: Team Report No. 1. Report on Industrially Healthy Hewers of Steam Coal......................................... 27 Clark, L. R., see Jordan, N. T. K. Clark, W. I.: The Dust Hazard in the Abrasive Industry: Third Study___343 Cummins, H. S.: The National Insti tute of Health of the United States Public Health Service....................... 1 Cummings, D. E., see Gardner, L. U. Gardner, L. IL. and Cummings, D. E.: Studies on Experimental Fneumonokonioeiv VI. Inhalation of Asbes tos Duet: Its Effect upon Primary Tuberculous Infection..................65, 87 Gilchrist, J. C., see Brownlee, A. Glover, D. M.: Beat Cramp* in Indus try: Their Treatment and Preven tion by Means of Sodium Chloride.. 647 Gloyno. 8. R.: A Method of Staining the Asbestos!* Bodies Found in the Sputum of Asbestos Worker*............ 86 Hersey, R. B.: The Subjective Side of Fatigue in Industry........................... 186 Hiley, R. M., see Brownlee, A. Johnson, A. C., eee Davies, W. Jordan, N. T. K., and Clark, L. R.: Coal Miners' Lung: Team Report No. 3. Radiographic Investigation of Healthy Coal Miners Carried Out at Craig-Y-Nos Hospital.................. 38 Kagan, M,, and Broumstein, W.: Ra tional Method for Calculating Rec ords Obtained by Means of Owens' Jet Dust Counting Apparatus........... 10 Kirk, E. J.: Hypertension in Industry. 314 Kouwenhoveu, W. B., see Langworthy, 0. R.(2). Krans, E. W., and Ficklen. J. B.: A Colorimetric Method for the Detec tion and Estimation of Small Amounts of Lead................................ 140 Davies, W., Johnson, A. C., and Thomas, J. L.: Coal Miners' Lung: Team Report No. 2. Report from the Cefn Mably Group on 41 Healthy Miners from the Nine Mile Point ana the Llanbradach Col lieries................. 32 Dudding, J. 8., Dudley, S. F.. and Fred erick, R. C.: The Production of Car bon Monoxide from Paint in Sealed Compartments................................... 333 Dudley, S. F., see Dudding, J. S. Lane, R. E.: The RAle of Punctate Basophilia in the Control of Indus trial Plumbism.................................... 276 Langworthy, O. R., and Kouwenhoven, W. B.: Tne Importance of the Points of Contact in Electric Injuries......... 146 Langworthy, O. R., and Kouwenhoven, W. B.: Injuries Produced in the Or ganism by the Discharge from an Im pulse Generator.................................. 326 McGavock, W., Jr., see Schlundt, H. ST085064 I AUTHOR INDEX Pedley, F. O., zee Ward, R. V. MOI Sohlundt, H., MoGavock, W., Jr., and Brown. M.: Dangers in Refining Ra dioactive Substances......................... 117 Schwartz, B.: Butcher*' Dermatitis.. 233 Smith, R. B., and Frii*, B. B. T.: Port able Motor-Driven Impinger Unit for Determination of Sulphur Diox ide....................................................... 338 Smyth, H. F.: The Toxicity of Certain Benzene Derivative! and Related Compounds......................................... 87 Smyth, H. F.. Jr.: Note on the Deter mination of Small Amounts of Ben zene Vapors in Air................................ 227 8omers, P. P., zee White, J. L. Stevens, H. W.: Employment "Sick ness and DeathRates'r...................... 50 raos Thomas, J. I,., zee Davies, W. Twort, C. Cv and Twort, J. M.: The Carcinogenic Potency of Mineral Oils....................................................... 204 Twort, J. M., zee Twort, C. C. von Bernewitz, M. W.: The So-Called Cyanide Rash.................................... 115 Ward, R. V., and Pedley, F. G.: A Night Industrial Dental Clinic in Montreal.............................................. 269 Warner, C. G., zee Bedford, T. (3). Weeks, W. S.: A New Instrument for Measuring Cooling Power: The Coolometer.................................................. 201 White. J. L., and Somers, P. P.: The Toxicity of Methyl Chloride for Laboratory Animals............................ 273 17 5 6 0 4